File Sharing Programs:
The Use of Peer-to-Peer Networks to Access Pornography
GAO-05-634, May 25, 2005
Peer-to-peer (P2P) file sharing programs represent a major change in the way Internet users find and exchange information. The increasingly popular P2P programs allow direct communication between computer users who can access and share digital music, images, and video files. These programs are known for having the functionality to share copyrighted digital music and movies, and they are also a conduit for sharing pornographic images and videos. Regarding these uses of P2P programs, GAO was asked to, among other things, determine how many P2P programs are available to the public and which are the most popular P2P programs; determine the ease of access to pornographic files on popular P2P programs and the risk of inadvertent exposure; describe how P2P program filters operate and determine their effectiveness; and determine how the effectiveness of filters offered by P2P programs compares to filters provided by leading Internet search engines. In commenting on a draft of this report, DHS officials agreed that that our report accurately represented the work performed by the Cyber Crimes Center.
According to three popular file sharing Web sites, 134 P2P programs are available to the public. Of those programs, Warez, Kazaa, and Morpheus were among the most popular, as of February 2005. Pornographic images are easily shared and accessed on the three P2P programs we tested--Warez, Kazaa, and Morpheus. Juveniles continue to be at risk of inadvertent exposure to pornographic images when using P2P programs. Two of the three P2P programs--Kazaa and Morpheus--provided filters intended to block access to objectionable material, but the effectiveness of the filters varied. Warez did not provide a filter. The filters provided by Kazaa and Morpheus functioned differently: Kazaa filtered words found in titles or metadata (data associated with the files that contain descriptive information), while Morpheus required the user to enter the specific words to be filtered. Kazaa's filter was effective in blocking pornographic and erotic images in our searches, but the Morpheus filter was largely ineffective in blocking pornographic content associated with words entered into the filter. The filters for the three leading Internet search engines--Google, Yahoo, and MSN--also varied in their effectiveness. MSN's filter was as effective as Kazaa's filter in consistently blocking pornographic and erotic images, while Google's filter was not as effective. Similar to Morpheus' filter, Yahoo's filter was largely ineffective in blocking pornographic and erotic images.