This letter formally transmits the briefing in response to the explanatory statement accompanying the Department of Homeland Security Appropriations Act, 2008 (Public Law 110-161, Division E). The statement directed the Comptroller General to report on its assessment of the Transportation Security Administration's (TSA) report to the Committees on Appropriations of the Senate and House of Representatives on the anticipated security benefits and vulnerabilities associated with TSA's decision to suspend enforcement of the prohibition on butane lighters onboard aircraft.