Anti-Flag is a punk rock band based in the United States, formed in 1988 in Pittsburgh, Pennsylvania, and known for its outspoken left-wing political views, focusing on anti-war activism, imperialism, class struggle, human rights, and other sociopolitical sentiments. Members include singer/guitarist Justin Sane, singer/bassist Chris Barker, guitarist Chris Head, and drummer Pat Thetic; Chris Barker ("Chris #2") replaced original bassist Andy Flag in 1999. The band is known also for their advocacy of progressive political action groups such as Greenpeace and Amnesty International.