Today a federal judge in Washington is scheduled to hear arguments against the congressional ban on mass-transit ads that criticize the war on drugs. In a striking example of drug warriors' disregard for civil liberties, the law authorizing transportation spending for 2004 threatens to withhold federal funds from transit authorities that accept ads promoting "the legalization or medical use of any substance listed in Schedule I…of the Controlled Substances Act." In February that threat led the Washington Metropolitan Area Transit Authority to reject an anti-drug-war ad submitted by the American Civil Liberties Union, Change the Climate, the Drug Policy Alliance, and the Marijuana Policy Project. Those groups are seeking to overturn the ban on First Amendment grounds. That should not be hard, since this is a clear case of discrimination based not just on content but on viewpoint.