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Testimony Before the Committee on the Judiciary: 
U.S. Senate:

For Release on Delivery Expected at 2 p.m. EDT on Tuesday September 9, 

File-Sharing Programs:

Users of Peer-to-Peer Networks Can Readily Access Child Pornography:

Statement of Linda D. Koontz Director, Information Managment Issues:


GAO Highlights:

Highlights of GAO-03-1115T, a testimony before the Committee on the 
Judiciary, United States Senate 

Why GAO Did This Study:

The availability of child pornography has dramatically increased in 
recent years as it has migrated from printed material to the World 
Wide Web, becoming accessible through Web sites, chat rooms, 
newsgroups, and now the increasingly popular peer-to-peer file sharing 
programs. These programs enable direct communication between users, 
allowing users to access each other’s files and share digital music, 
images, and video. 

GAO was requested to determine the ease of access to child pornography 
on peer-to-peer networks; the risk of inadvertent exposure of juvenile 
users of peer-to-peer networks to pornography, including child 
pornography; and the extent of federal law enforcement resources 
available for combating child pornography on peer-to-peer networks. 
Today’s testimony is based on GAO’s report on the results of that work 

Because child pornography cannot be accessed legally other than by law 
enforcement agencies, GAO worked with the Customs CyberSmuggling 
Center in performing searches: Customs downloaded and analyzed image 
files, and GAO performed analyses based on keywords and file names 

What GAO Found:

Child pornography is easily found and downloaded from peer-to-peer 
networks. In one search, using 12 keywords known to be associated with 
child pornography on the Internet, GAO identified 1,286 titles and 
file names, determining that 543 (about 42 percent) were associated 
with child pornography images. Of the remaining, 34 percent were 
classified as adult pornography and 24 percent as nonpornographic. In 
another search using three keywords, a Customs analyst downloaded 341 
images, of which 149 (about 44 percent) contained child pornography 
(see the figure below). These results are in accord with increased 
reports of child pornography on peer-to-peer networks; since it began 
tracking these in 2001, the National Center for Missing and Exploited 
Children has seen a fourfold increase—from 156 in 2001 to 757 in 2002. 
Although the numbers are as yet small by comparison to those for other 
sources (26,759 reports of child pornography on Web sites in 2002), 
the increase is significant.

Juvenile users of peer-to-peer networks are at significant risk of 
inadvertent exposure to pornography, including child pornography. 
Searches on innocuous keywords likely to be used by juveniles (such as 
names of cartoon characters or celebrities) produced a high proportion 
of pornographic images: in our searches, the retrieved images included 
adult pornography (34 percent), cartoon pornography (14 percent), 
child erotica (7 percent), and child pornography (1 percent). 

While federal law enforcement agencies—including the FBI, Justice’s 
Child Exploitation and Obscenity Section, and Customs—are devoting 
resources to combating child exploitation and child pornography in 
general, these agencies do not track the resources dedicated to 
specific technologies used to access and download child pornography on 
the Internet. Therefore, GAO was unable to quantify the resources 
devoted to investigating cases on peer-to-peer networks. According to 
law enforcement officials, however, as tips concerning child 
pornography on peer-to-peer networks escalate, law enforcement 
resources are increasingly being focused on this area.

To view the full testimony, click on the link above. For more 
information, contact Linda Koontz at (202) 512-6240 or

[End of section]

Mr. Chairman and Members of the Committee:

Thank you for inviting us to discuss our work on the availability of 
child pornography on peer-to-peer networks.[Footnote 1]

In recent years, child pornography has become increasingly available as 
it has migrated from magazines, photographs, and videos to the World 
Wide Web. As you know, a great strength of the Internet is that it 
includes a wide range of search and retrieval technologies that make 
finding information fast and easy. However, this capability also makes 
it easy to access, disseminate, and trade pornographic images and 
videos, including child pornography. As a result, child pornography has 
become accessible through Web sites, chat rooms, newsgroups, and the 
increasingly popular peer-to-peer technology, a form of networking that 
allows direct communication between computer users so that they can 
access and share each other's files (including images, video, and 

As requested, in my remarks today, I will summarize the results of a 
review that we recently conducted to determine:

* the ease of access to child pornography on peer-to-peer networks;

* the risk of inadvertent exposure of juvenile users of peer-to-peer 
networks to pornography, including child pornography; and:

* the extent of federal law enforcement resources available for 
combating child pornography on peer-to-peer networks.

We also include an attachment that briefly discusses how peer-to-peer 
file sharing works.

Results in Brief:

It is easy to access and download child pornography over peer-to-peer 
networks. We used KaZaA, a popular peer-to-peer file-sharing 
program,[Footnote 2] to search for image files, using 12 keywords known 
to be associated with child pornography on the Internet.[Footnote 3] Of 
1,286 items identified in our search, about 42 percent were associated 
with child pornography images. The remaining items included 34 percent 
classified as adult pornography and 24 percent as nonpornographic. In 
another KaZaA search, the Customs CyberSmuggling Center used three 
keywords to search for and download child pornography image files. This 
search identified 341 image files, of which about 44 percent were 
classified as child pornography and 29 percent as adult pornography. 
The remaining images were classified as child erotica[Footnote 4] (13 
percent) or other (nonpornographic) images (14 percent). These results 
are consistent with observations of the National Center for Missing and 
Exploited Children, which has stated that peer-to-peer technology is 
increasingly popular for the dissemination of child pornography. Since 
2001, when the center began to track reports of child pornography on 
peer-to-peer networks, such reports have increased more than fourfold-
-from 156 in 2001 to 757 in 2002.

When searching and downloading images on peer-to-peer networks, 
juvenile users can be inadvertently exposed to pornography, including 
child pornography. In searches on innocuous keywords likely to be used 
by juveniles, we obtained images that included a high proportion of 
pornography: in our searches, the retrieved images included adult 
pornography (34 percent), cartoon pornography[Footnote 5] (14 percent), 
and child pornography (1 percent); another 7 percent of the images were 
classified as child erotica.

We could not quantify the extent of federal law enforcement resources 
available for combating child pornography on peer-to-peer networks. Law 
enforcement agencies that work to combat child exploitation and child 
pornography do not track their resource use according to specific 
Internet technologies. However, law enforcement officials told us that 
as they receive more tips concerning child pornography on peer-to-peer 
networks, they are focusing more resources in this area.


Child pornography is prohibited by federal statutes, which provide for 
civil and criminal penalties for its production, advertising, 
possession, receipt, distribution, and sale.[Footnote 6] Defined by 
statute as the visual depiction of a minor--a person under 18 years of 
age--engaged in sexually explicit conduct,[Footnote 7] child 
pornography is unprotected by the First Amendment,[Footnote 8] as it is 
intrinsically related to the sexual abuse of children.

In the Child Pornography Prevention Act of 1996,[Footnote 9] Congress 
sought to prohibit images that are or appear to be "of a minor engaging 
in sexually explicit conduct" or are "advertised, promoted, presented, 
described, or distributed in such a manner that conveys the impression 
that the material is or contains a visual depiction of a minor engaging 
in sexually explicit conduct." In 2002, the Supreme Court struck down 
this legislative attempt to ban "virtual" child pornography[Footnote 
10] in Ashcroft v. The Free Speech Coalition, ruling that the expansion 
of the act to material that did not involve and thus harm actual 
children in its creation is an unconstitutional violation of free 
speech rights. According to government officials, this ruling may 
increase the difficulty of prosecuting those who produce and possess 
child pornography. Defendants may claim that pornographic images are of 
"virtual" children, thus requiring the government to establish that the 
children shown in these digital images are real. Recently, Congress 
enacted the PROTECT Act,[Footnote 11] which attempts to address the 
constitutional issues raised in The Free Speech Coalition 
decision.[Footnote 12]

The Internet Has Emerged as the Principal Tool for Exchanging Child 

Historically, pornography, including child pornography, tended to be 
found mainly in photographs, magazines, and videos.[Footnote 13] With 
the advent of the Internet, however, both the volume and the nature of 
available child pornography have changed significantly. The rapid 
expansion of the Internet and its technologies, the increased 
availability of broadband Internet services, advances in digital 
imaging technologies, and the availability of powerful digital graphic 
programs have led to a proliferation of child pornography on the 

According to experts, pornographers have traditionally exploited--and 
sometimes pioneered--emerging communication technologies--from the 
dial-in bulletin board systems of the 1970s to the World Wide Web--to 
access, trade, and distribute pornography, including child 
pornography.[Footnote 14] Today, child pornography is available through 
virtually every Internet technology (see table 1).

Table 1: Internet Technologies Providing Access to Child Pornography: 

Technology: World Wide Web; Characteristics: Web sites provide on-line 
access to text and multimedia materials identified and accessed through 
the uniform resource locator (URL). 

Technology: Usenet; Characteristics: A distributed electronic bulletin 
system, Usenet offers over 80,000 newsgroups, with many newsgroups 
dedicated to sharing of digital images. 

Technology: Peer-to-peer file-sharing programs; Characteristics: 
Internet applications operating over peer-to-peer networks enable 
direct communication between users. Used largely for sharing of digital 
music, images, and video, peer-to-peer applications include BearShare, 
Gnutella, LimeWire, and KaZaA. KaZaA is the most popular, with over 3 
million KaZaA users sharing files at any time. 

Technology: E-mail; Characteristics: E-mail allows the transmission of 
messages over a network or the Internet. Users can send E-mail to a 
single recipient or broadcast it to multiple users. E-mail supports the 
delivery of attached files, including image files. 

Technology: Instant messaging; Characteristics: Instant messaging is 
not a dial-up system like the telephone; it requires that both parties 
be on line at the same time. AOL's Instant Messenger and Microsoft's 
MSN Messenger and Internet Relay Chat are the major instant messaging 
services. Users may exchange files, including image files. 

Technology: Chat and Internet Relay Chat; Characteristics: Chat 
technologies allow computer conferencing using the keyboard over the 
Internet between two or more people. 

Source: GAO.

[End of table]

Among the principal channels for the distribution of child pornography 
are commercial Web sites, Usenet newsgroups, and peer-to-peer 
networks.[Footnote 15]

Web sites. According to recent estimates, there are about 400,000 
commercial pornography Web sites worldwide,[Footnote 16] with some of 
the sites selling pornographic images of children. The child 
pornography trade on the Internet is not only profitable, it has a 
worldwide reach: recently a child pornography ring was uncovered that 
included a Texas-based firm providing credit card billing and password 
access services for one Russian and two Indonesian child pornography 
Web sites. According to the U.S. Postal Inspection Service, the ring 
grossed as much as $1.4 million in just 1 month selling child 
pornography to paying customers.

Usenet. Usenet newsgroups also provide access to pornography, with 
several of the image-oriented newsgroups being focused on child erotica 
and child pornography. These newsgroups are frequently used by 
commercial pornographers who post "free" images to advertise adult and 
child pornography available for a fee from their Web sites.

Peer-to-peer networks. Although peer-to-peer file-sharing programs are 
largely known for the extensive sharing of copyrighted digital 
music,[Footnote 17] they are emerging as a conduit for the sharing of 
pornographic images and videos, including child pornography. In a 
recent study by congressional staff,[Footnote 18] a single search for 
the term "porn" using a file-sharing program yielded over 25,000 files. 
In another study, focused on the availability of pornographic video 
files on peer-to-peer sharing networks, a sample of 507 pornographic 
video files retrieved with a file-sharing program included about 3.7 
percent child pornography videos.[Footnote 19]

Several Agencies Have Law Enforcement Responsibilities Regarding Child 
Pornography on Peer-to-Peer Networks:

Table 2 shows the key national organizations and agencies that are 
currently involved in efforts to combat child pornography on peer-to-
peer networks.

Table 2: Organizations and Agencies Involved with Peer-to-Peer 
Child Pornography Efforts:

Agency: Nonprofit: 

Agency: National Center for Missing and Exploited Children; Unit: 
Exploited Child Unit; Focus: Works with the Customs Service, Postal 
Service, and the FBI to analyze and investigate child pornography 

Agency: Federal entities: 

Agency: Department of Justice; Unit: Federal Bureau of Investigation[
A]; Focus: Proactively investigates crimes against children. Operates a 
national "Innocent Images Initiative" to combat Internet-related sexual 
exploitation of children. 

Unit: Criminal Division, Child Exploitation and Obscenity Section; 
Focus: Is a specialized group of attorneys who, among other things, 
prosecute those who possess, manufacture, or distribute child 
pornography. Its High Tech Investigative Unit actively conducts on-line 
investigations to identify distributors of obscenity and child 

Agency: Department of Homeland Security; Unit: U.S. Customs Service 
CyberSmuggling Center[A,B]; Focus: Conducts international child 
pornography investigations as part of its mission to investigate 
international criminal activity conducted on or facilitated by the 

Agency: Department of the Treasury; Unit: U.S. Secret Service[A]; 
Focus: Provides forensic and technical assistance in matters involving 
missing and sexually exploited children. 

Source: GAO.

[A] Agency has staff assigned to NCMEC.

[B] At the time of our review, the Customs Service was under the 
Department of the Treasury. Under the Homeland Security Act of 2002, it 
became part of the new Department of Homeland Security on March 1, 

[End of table]

The National Center for Missing and Exploited Children (NCMEC), a 
federally funded nonprofit organization, serves as a national resource 
center for information related to crimes against children. Its mission 
is to find missing children and prevent child victimization. The 
center's Exploited Child Unit operates the CyberTipline, which receives 
child pornography tips provided by the public; its CyberTipline II also 
receives tips from Internet service providers. The Exploited Child Unit 
investigates and processes tips to determine if the images in question 
constitute a violation of child pornography laws. The CyberTipline 
provides investigative leads to the Federal Bureau of Investigation 
(FBI), U.S. Customs, the Postal Inspection Service, and state and local 
law enforcement agencies. The FBI and the U.S. Customs also investigate 
leads from Internet service providers via the Exploited Child Unit's 
CyberTipline II. The FBI, Customs Service, Postal Inspection Service, 
and Secret Service have staff assigned directly to NCMEC as 
analysts.[Footnote 20]

Two organizations in the Department of Justice have responsibilities 
regarding child pornography: the FBI and the Justice Criminal 
Division's Child Exploitation and Obscenity Section (CEOS).[Footnote 

* The FBI investigates various crimes against children, including 
federal child pornography crimes involving interstate or foreign 
commerce. It deals with violations of child pornography laws related to 
the production of child pornography; selling or buying children for use 
in child pornography; and the transportation, shipment, or distribution 
of child pornography by any means, including by computer.

* CEOS prosecutes child sex offenses and trafficking in women and 
children for sexual exploitation. Its mission includes prosecution of 
individuals who possess, manufacture, produce, or distribute child 
pornography; use the Internet to lure children to engage in prohibited 
sexual conduct; or traffic in women and children interstate or 
internationally to engage in sexually explicit conduct.

Two other organizations have responsibilities regarding child 
pornography: the Customs Service (now part of the Department of 
Homeland Security) and the Secret Service in the Department of the 

* The Customs Service targets illegal importation and trafficking in 
child pornography and is the country's front line of defense in 
combating child pornography distributed through various channels, 
including the Internet. Customs is involved in cases with international 
links, focusing on pornography that enters the United States from 
foreign countries. The Customs CyberSmuggling Center has the lead in 
the investigation of international and domestic criminal activities 
conducted on or facilitated by the Internet, including the sharing and 
distribution of child pornography on peer-to-peer networks. Customs 
maintains a reporting link with NCMEC, and it acts on tips received via 
the CyberTipline from callers reporting instances of child pornography 
on Web sites, Usenet newsgroups, chat rooms, or the computers of users 
of peer-to-peer networks. The center also investigates leads from 
Internet service providers via the Exploited Child Unit's CyberTipline 

* The U.S. Secret Service does not investigate child pornography cases 
on peer-to-peer networks; however, it does provide forensic and 
technical support to NCMEC, as well as to state and local agencies 
involved in cases of missing and exploited children.

Peer-to-Peer Applications Provide Easy Access to Child Pornography:

Child pornography is easily shared and accessed through peer-to-peer 
file-sharing programs. Our analysis of 1,286 titles and file names 
identified through KaZaA searches on 12 keywords[Footnote 22] showed 
that 543 (about 42 percent) of the images had titles and file names 
associated with child pornography images.[Footnote 23] Of the remaining 
files, 34 percent were classified as adult pornography, and 24 percent 
as nonpornographic (see fig. 1). No files were downloaded for this 

Figure 1: Classification of 1,286 Titles and File Names of Images 
Identified in KaZaA Search:

[See PDF for image]

[End of figure]

The ease of access to child pornography files was further documented by 
retrieval and analysis of image files, performed on our behalf by the 
Customs CyberSmuggling Center. Using 3 of the 12 keywords that we used 
to document the availability of child pornography files, a 
CyberSmuggling Center analyst used KaZaA to search, identify, and 
download 305 files, including files containing multiple images and 
duplicates. The analyst was able to download 341 images from the 305 
files identified through the KaZaA search.

The CyberSmuggling Center analysis of the 341 downloaded images showed 
that 149 (about 44 percent) of the downloaded images contained child 
pornography (see fig. 2). The center classified the remaining images as 
child erotica (13 percent), adult pornography (29 percent), or 
nonpornographic (14 percent).

Figure 2: Classification of 341 Images Downloaded through KaZaA:

[See PDF for image]

Note: GAO analysis of data provided by the Customs CyberSmuggling 

[End of figure]

These results are consistent with the observations of NCMEC, which has 
stated that peer-to-peer technology is increasingly popular for the 
dissemination of child pornography. However, it is not the most 
prominent source for child pornography. As shown in table 3, since 
1998, most of the child pornography referred by the public to the 
CyberTipline was found on Internet Web sites. Since 1998, the center 
has received over 76,000 reports of child pornography, of which 77 
percent concerned Web sites, and only 1 percent concerned peer-to-peer 
networks. Web site referrals have grown from about 1,400 in 1998 to 
over 26,000 in 2002--or about a nineteenfold increase. NCMEC did not 
track peer-to-peer referrals until 2001. In 2002, peer-to-peer 
referrals increased more than fourfold, from 156 to 757, reflecting the 
increased popularity of file-sharing programs.

Table 3: NCMEC CyberTipline Referrals to Law Enforcement Agencies, 
Fiscal Years 1998-2002:

Technology: Web sites; Number of tips: 1998: 1,393; Number of 
tips: 1999: 3,830; Number of tips: 2000: 10,629; Number of tips: 2001: 
18,052; Number of tips: 2002: 26,759.

Technology: E-mail; Number of tips: 1998: 117; Number of tips: 
1999: 165; Number of tips: 2000: 120; Number of tips: 2001: 1,128; 
Number of tips: 2002: 6,245.

Technology: Peer-to-peer; Number of tips: 1998: -; Number of 
tips: 1999: -; Number of tips: 2000: -; Number of tips: 2001: 156; 
Number of tips: 2002: 757.

Technology: Usenet newsgroups & bulletin boards; Number of 
tips: 1998: 531; Number of tips: 1999: 987; Number of tips: 2000: 731; 
Number of tips: 2001: 990; Number of tips: 2002: 993.

Technology: Unknown; Number of tips: 1998: 90; Number of tips: 
1999: 258; Number of tips: 2000: 260; Number of tips: 2001: 430; Number 
of tips: 2002: 612.

Technology: Chat rooms; Number of tips: 1998: 155; Number of 
tips: 1999: 256; Number of tips: 2000: 176; Number of tips: 2001: 125; 
Number of tips: 2002: 234.

Technology: Instant Messaging; Number of tips: 1998: 27; 
Number of tips: 1999: 47; Number of tips: 2000: 50; Number of tips: 
2001: 80; Number of tips: 2002: 53.

Technology: File Transfer Protocol; Number of tips: 1998: 25; 
Number of tips: 1999: 26; Number of tips: 2000: 58; Number of tips: 
2001: 64; Number of tips: 2002: 23.

Technology: Total; Number of tips: 1998: 2,338; Number of 
tips: 1999: 5,569; Number of tips: 2000: 12,024; Number of tips: 2001: 
21,025; Number of tips: 2002: 35,676.

Source: Exploited Child Unit, National Center for Missing and Exploited 

[End of table]
Juvenile Users of Peer-to-Peer Applications May Be Inadvertently 
Exposed to Pornography:

Juvenile users of peer-to-peer networks face a significant risk of 
inadvertent exposure to pornography when searching and downloading 
images. In a search using innocuous keywords likely to be used by 
juveniles searching peer-to-peer networks (such as names of popular 
singers, actors, and cartoon characters), almost half the images 
downloaded were classified as adult or cartoon pornography. Juvenile 
users may also be inadvertently exposed to child pornography through 
such searches, but the risk of such exposure is smaller than that of 
exposure to pornography in general.

To document the risk of inadvertent exposure of juvenile users to 
pornography, the Customs CyberSmuggling Center performed KaZaA searches 
using innocuous keywords likely to be used by juveniles. The center 
image searches used three keywords representing the names of a popular 
female singer, child actors, and a cartoon character. A center analyst 
performed the search, retrieval, and analysis of the images. These 
searches produced 157 files, some of which were duplicates. From these 
157 files, the analyst was able to download 177 images..

Figure 3 shows our analysis of the CyberSmuggling Center's 
classification of the 177 downloaded images. We determined that 61 
images contained adult pornography (34 percent), 24 images consisted of 
cartoon pornography (14 percent), 13 images contained child erotica (7 
percent), and 2 images (1 percent) contained child pornography. The 
remaining 77 images were classified as nonpornographic.

Figure 3: Classification of 177 Images of a Popular Singer, Child 
Actors, and a Cartoon Character Downloaded through KaZaA:

[See PDF for image]

[End of figure]

Federal Law Enforcement Agencies Are Beginning to Focus Resources on 
Child Pornography on Peer-to-Peer Networks:

Because law enforcement agencies do not track the resources dedicated 
to specific technologies used to access and download child pornography 
on the Internet, we were unable to quantify the resources devoted to 
investigations concerning peer-to-peer networks. These agencies 
(including the FBI, CEOS, and Customs) do devote significant resources 
to combating child exploitation and child pornography in general. Law 
enforcement officials told us, however, that as tips concerning child 
pornography on the peer-to-peer networks increase, they are beginning 
to focus more law enforcement resources on this issue. Table 4 shows 
the levels of funding related to child pornography issues that the 
primary organizations reported for fiscal year 2002, as well as a 
description of their efforts regarding peer-to-peer networks in 

Table 4: Resources Related to Combating Child Pornography on Peer-to-
Peer Networks in 2002:

Organization: National Center for Missing and Exploited Children; 
Resources[A]: $12 million to act as national resource center and 
clearinghouse for missing and exploited children; $10 million for law 
enforcement training; $3.3 million for the Exploited Child Unit and the 
CyberTipline; $916,000 allocated to combat child pornography; Efforts 
regarding peer-to-peer networks: NCMEC referred 913 tips concerning 
peer-to-peer networks to law enforcement agencies. 

Organization: Federal Bureau of Investigation; Resources[A]: $38.2 
million and 228 agents and support personnel for Innocent Images Unit; 
Efforts regarding peer-to-peer networks: According to FBI officials, 
they have efforts under way to work with some of the peer-to-peer 
companies to solicit their cooperation in dealing with the issue of 
child pornography. 

Organization: Justice Criminal Division, Child Exploitation and 
Obscenity Section; Resources[A]: $4.38 million and 28 personnel 
allocated to combating child exploitation and obscenity offenses; 
Efforts regarding peer-to-peer networks: The High Tech Investigative 
Unit deals with investigating any Internet medium that distributes 
child pornography, including peer-to-peer networks. 

Organization: U.S. Customs Service CyberSmuggling Center; 
Resources[A]: $15.6 million (over 144,000 hours) allocated to 
combating child exploitation and obscenity offenses[B]; Efforts 
regarding peer-to-peer networks: The center is beginning to actively 
monitor peer-to-peer networks for child pornography, devoting one half-
time investigator to this effort. As of December 16, 2002, the center 
had sent 21 peer-to-peer investigative leads to field offices for 

Source: GAO and agencies mentioned.

[A] Dollar amounts are approximate.

[B] Customs was unable to separate the staff hours devoted or funds 
obligated to combating child pornography from those dedicated to 
combating child exploitation in general.

[End of table]

An important new resource to facilitate the identification of the 
victims of child pornographers is the National Child Victim 
Identification Program, run by the CyberSmuggling Center. This resource 
is a consolidated information system containing seized images that is 
designed to allow law enforcement officials to quickly identify and 
combat the current abuse of children associated with the production of 
child pornography. The system's database is being populated with all 
known and unique child pornographic images obtained from national and 
international law enforcement sources and from CyberTipline reports 
filed with NCMEC. It will initially hold over 100,000 images collected 
by federal law enforcement agencies from various sources, including old 
child pornography magazines.[Footnote 24] According to Customs 
officials, this information will help, among other things, to determine 
whether actual children were used to produce child pornography images 
by matching them with images of children from magazines published 
before modern imaging technology was invented. Such evidence can be 
used to counter the assertion that only virtual children appear in 
certain images.

The system, which became operational in January 2003,[Footnote 25] is 
housed at the Customs CyberSmuggling Center and can be accessed 
remotely in "read only" format by the FBI, CEOS, the U.S. Postal 
Inspection Service, and NCMEC.

In summary, Mr. Chairman, our work shows that child pornography as well 
as adult pornography is widely available and accessible on peer-to-peer 
networks. Even more disturbing, we found that peer-to-peer searches 
using seemingly innocent terms that clearly would be of interest to 
children produced a high proportion of pornographic material, including 
child pornography. The increase in reports of child pornography on 
peer-to-peer networks suggests that this problem is increasing. As a 
result, it will be important for law enforcement agencies to follow 
through on their plans to devote more resources to this technology and 
continue their efforts to develop effective strategies for addressing 
this problem.

Mr. Chairman, this concludes my statement. I would be pleased to answer 
any questions that you or other Members of the Committee may have at 
this time.

Contact and Acknowledgments:

If you should have any questions about this testimony, please contact 
me at (202) 512-6240 or by E-mail at [Hyperlink,] Key contributors to this testimony were Barbara S. 
Collier, Mirko Dolak, James M. Lager, Neelaxi V. Lakhmani, James R. 
Sweetman, Jr., and Jessie Thomas.

[End of section]

Attachment I: How File Sharing Works on Peer-to-Peer Networks:

Peer-to-peer file-sharing programs represent a major change in the way 
Internet users find and exchange information. Under the traditional 
Internet client/server model, access to information and services is 
accomplished by interaction between clients--users who request 
services--and servers--providers of services, usually Web sites or 
portals. Unlike this traditional model, the peer-to-peer model enables 
consenting users--or peers--to directly interact and share information 
with each other, without the intervention of a server. A common 
characteristic of peer-to-peer programs is that they build virtual 
networks with their own mechanisms for routing message 
traffic.[Footnote 26]

The ability of peer-to-peer networks to provide services and connect 
users directly has resulted in a large number[Footnote 27] of powerful 
applications built around this model.[Footnote 28] These range from the 
[Hyperlink, SETI@home] SETI@home network (where users share the 
computing power of their computers to search for extraterrestrial life) 
to the popular KaZaA file-sharing program (used to share music and 
other files).

As shown in figure 4,[Footnote 29] there are two main models of peer-
to-peer networks: (1) the centralized model, in which a central server 
or broker directs traffic between individual registered users, and 
(2) the decentralized model, based on the Gnutella[Footnote 30] 
network, in which individuals find each other and interact directly.

Figure 4: Peer-to-Peer Models:

[See PDF for image]

[End of figure]

As shown in figure 4, in the centralized model, a central server/broker 
maintains directories of shared files stored on the computers of 
registered users. When Bob submits a request for a particular file, the 
server/broker creates a list of files matching the search request by 
checking it against its database of files belonging to users currently 
connected to the network. The broker then displays that list to Bob, 
who can then select the desired file from the list and open a direct 
link with Alice's computer, which currently has the file. The download 
of the actual file takes place directly from Alice to Bob.

This broker model was used by Napster, the original peer-to-peer 
network, facilitating mass sharing of material by combining the file 
names held by thousands of users into a searchable directory that 
enabled users to connect with each other and download MP3 encoded music 
files. Because much of this material was copyrighted, Napster as the 
broker of these exchanges was vulnerable to legal challenges,[Footnote 
31] which eventually led to its demise in September 2002.

In contrast to Napster, most current-generation peer-to-peer networks 
are decentralized. Because they do not depend on the server/broker that 
was the central feature of the Napster service, these networks are less 
vulnerable to litigation from copyright owners, as pointed out by 
Gartner.[Footnote 32]

In the decentralized model, no brokers keep track of users and their 
files. To share files using the decentralized model, Ted starts with a 
networked computer equipped with a Gnutella file-sharing program such 
KaZaA or BearShare. Ted connects to Carol, Carol to Bob, Bob to Alice, 
and so on. Once Ted's computer has announced that it is "alive" to the 
various members of the peer network, it can search the contents of the 
shared directories of the peer network members. The search request is 
sent to all members of the network, starting with Carol; members will 
in turn send the request to the computers to which they are connected, 
and so forth. If one of the computers in the peer network (say, for 
example, Alice's) has a file that matches the request, it transmits the 
file information (name, size, type, etc.) back through all the 
computers in the pathway towards Ted, where a list of files matching 
the search request appears on Ted's computer through the file-sharing 
program. Ted can then open a connection with Alice and download the 
file directly from Alice's computer.[Footnote 33]

The file-sharing networks that result from the use of peer-to-peer 
technology are both extensive and complex. Figure 5 shows a map or 
topology of a Gnutella network whose connections were mapped by a 
network visualization tool.[Footnote 34] The map, created in December 
2000, shows 1,026 nodes (computers connected to more than one computer) 
and 3,752 edges (computers on the edge of the network connected to a 
single computer). This map is a snapshot showing a network in existence 
at a given moment; these networks change constantly as users join and 
depart them.

Figure 5: Topology of a Gnutella Network:

[See PDF for image]

[End of figure]

One of the key features of many peer-to-peer technologies is their use 
of a virtual name space (VNS). A VNS dynamically associates user-
created names with the Internet address of whatever Internet-connected 
computer users happen to be using when they log on.[Footnote 35] The 
VNS facilitates point-to-point interaction between individuals, 
because it removes the need for users and their computers to know the 
addresses and locations of other users; the VNS can, to certain extent, 
preserve users' anonymity and provide information on whether a user is 
or is not connected to the Internet at a given moment. Peer-to-peer 
users thus may appear to be anonymous; they are not, however. Law 
enforcement agents may identify users' Internet addresses during the 
file-sharing process and obtain, under a court order, their identities 
from their Internet service providers.



[1] U.S. General Accounting Office, File-Sharing Programs: Peer-to-Peer 
Networks Provide Ready Access to Child Pornography, GAO-03-351 
(Washington, D.C.: Feb. 20, 2003). 

[2] Other popular peer-to-peer applications include Gnutella, 
BearShare, LimeWire, and Morpheus.

[3] The U.S. Customs CyberSmuggling Center assisted us in this work. 
Because child pornography cannot be accessed legally other than by law 
enforcement agencies, we relied on Customs to download and analyze 
image files. We performed analyses based on titles and file names only.

[4] Erotic images of children that do not depict sexually explicit 

[5] Images of cartoon characters depicting sexually explicit conduct. 

[6] See chapter 110 of Title 18, United States Code.

[7] See 18 U.S.C. § 2256(8). 

[8] See New York v. Ferber, 458 U.S. 747 (1982).

[9] Section 121, P.L. 104-208, 110 Stat. 3009-26.

[10] According to the Justice Department, rapidly advancing technology 
has raised the possibility of creating images of child pornography 
without the use of a real child ("virtual" child pornography). Totally 
virtual creations would be both time-intensive and, for now, 
prohibitively costly to produce. However, the technology has led to a 
ready defense (the "virtual" porn defense) against prosecution under 
laws that are limited to sexually explicit depictions of actual minors. 
Because the technology exists today to alter images to disguise the 
identity of the real child or make the image seem computer-generated, 
producers and distributors of child pornography may try to alter 
depictions of actual children in slight ways to make them appear to be 
"virtual" (as well as unidentifiable), thereby attempting to defeat 
prosecution. Making such alterations is much easier and cheaper than 
building an entirely computer-generated image. 

[11] Public Law No. 108-21 (Apr. 30, 2003).

[12] S. Rep. No. 108-2, at 13 (2003).

[13] John Carr, Theme Paper on Child Pornography for the 2ND World 
Congress on Commercial Sexual Exploitation of Children, NCH Children's 
Charities, Children & Technology Unit (Yokohama, 2001). (http://

[14] Frederick E. Allen, "When Sex Drives Technological Innovation and 
Why It Has to," American Heritage Magazine, vol. 51, no. 5 (September 
2000), p. 19. (
updatearch.html) Allen notes that pornographers have driven the 
development of some of the Internet technologies, including the 
development of systems used to verify on-line financial transactions 
and that of digital watermarking technology to prevent the unauthorized 
use of on-line images.

[15] According to Department of Justice officials, other forums and 
technologies are used to disseminate pornography on the Internet. These 
include Web portal communities such as Yahoo! Groups and MSN Groups, as 
well as file servers operating on Internet Relay Chat channels.

[16] Dick Thornburgh and Herbert S. Lin, editors, Youth, Pornography, 
and The Internet, National Academy Press (Washington, D.C.: 2002). 

[17] According to the Yankee Group, a technology research and 
consulting firm, Internet users aged 14 and older downloaded 5.16 
billion audio files in the United States via unlicensed file-sharing 
services in 2001.

[18] Minority Staff, Children's Access to Pornography through Internet 
File-Sharing Programs, Special Investigations Division, Committee on 
Government Reform, U.S. House of Representatives (July 27, 2001). 

[19] Michael D. Mehta, Don Best, and Nancy Poon, "Peer-to-Peer Sharing 
on the Internet: An Analysis of How Gnutella Networks Are Used to 
Distribute Pornographic Material," Canadian Journal of Law and 
Technology, vol. 1, no. 1 (January 2002). (

[20] According to the Secret Service, its staff assigned to NCMEC also 
includes an agent.

[21] Two additional Justice agencies are involved in combating child 
pornography: the U.S. Attorneys Offices and the Office of Juvenile 
Justice and Delinquency Prevention. The 94 U.S. Attorneys Offices can 
prosecute federal child exploitation-related cases; the Office of 
Juvenile Justice and Delinquency Prevention funds the Internet Crimes 
Against Children Task Force Program, which encourages 
multijurisdictional and multiagency responses to crimes against 
children involving the Internet.

[22] The 12 keywords were provided by the Cybersmuggling Center as 
examples known to be associated with child pornography on the Internet.

[23] We categorized a file as child pornography if one keyword 
indicating a minor and one word with a sexual connotation occurred in 
either the title or file name. Files with sexual connotation in title 
or name but without age indicators were classified as adult 

[24] According to federal law enforcement agencies, most of the child 
pornography published before 1970 has been digitized and made widely 
available on the Internet.

[25] One million dollars has already been spent on the system, with an 
additional $5 million needed for additional hardware, the expansion of 
the image database, and access for all involved agencies. The 10-year 
lifecycle cost of the system is estimated to be $23 million.

[26] Matei Ripenau, Ian Foster, and Adriana Iamnitchi, "Mapping the 
Gnutella Network: Properties of Large Scale Peer-to-Peer Systems and 
Implication for System Design," IEEE Internet Computing, vol. 6, no. 1 
(January-February 2002). (

[27], a file-sharing portal, lists 88 different peer-to-
peer file-sharing programs available for download. (http://

[28] Geoffrey Fox and Shrideep Pallickara, "Peer-to-Peer Interactions 
in Web Brokering Systems," Ubiquity, vol. 3, no. 15 (May 28-June 3, 
2002) (published by Association of Computer Machinery). (http://

[29] Illustration adapted by Lt. Col. Mark Bontrager from original by 
Bob Knighten, "Peer-to-Peer Computing," briefing to Peer-to-Peer 
Working Groups (August 24, 2000), in Mark D. Bontrager, Peering into 
the Future: Peer-to-Peer Technology as a Model for Distributed Joint 
Battlespace Intelligence Dissemination and Operational Tasking, 
Thesis, School of Advanced Airpower Studies, Air University, Maxwell 
Air Force Base, Alabama (June 2001). 

[30] According to LimeWire LLC, the developer of a popular file-sharing 
program, Gnutella was originally designed by Nullsoft, a subsidiary of 
America Online. The development of the Gnutella protocol was halted by 
AOL management shortly after the protocol was made available to the 
public. Using downloads, programmers reverse-engineered the software 
and created their own Gnutella software packages. (http://

[31] A&M Records v. Napster, 114 F.Supp.2d 896 (N.D. Cal. 2000).

[32] Lydia Leong, "RIAA vs.Verizon, Implications for ISPs," Gartner 
(Oct. 24, 2002).

[33] LimeWire, Modern Peer-to-Peer File Sharing over the Internet. 

[34] Mihajlo A. Jovanovic, Fred S. Annexstein, and Kenneth A. Berman, 
Scalability Issues in Large Peer-to-Peer Networks: A Case Study of 
Gnutella, University of Cincinnati Technical Report (2001). (http://

[35] S. Hayward and R. Batchelder, "Peer-to-Peer: Something Old, 
Something New," Gartner (Apr. 10, 2001).