No. 06-5324. Argued February 16, 2007. Decided April 6, 2007. Appeal from the United States District Court for the District of Columbia (No. 06cv01455). Joseph Margulies argued the cause for appellants. With him on the briefs were Jonathan L. Hafetz, Aziz Z. Huq, Eric M. Freedman, and Susan L. Burke. Gregory G. Garre, Deputy Solicitor General, U.S. Department of Justice, argued the cause for appellees. With him on the brief were Peter D. Keisler, Assistant Attorney General, Jeffrey A. Taylor, U.S