Anti-Flag are an American punk rock band from Pittsburgh, Pennsylvania, United States. The band is well known for politically charged lyrics and activism, focusing on anti-war activism, anti-imperialism, class struggle, human rights, and various sociopolitical sentiments. The line-up includes singer/guitarist Justin Sane and drummer Pat Thetic, who founded the band; later members are guitarist Chris Head, and singer/bassist Chris Barker (#2) who replaced Jamie "Cock" Towns, who had replaced original bassist Andy Flag in 1997 following his departure one year prior. Anti-Flag is known also for their advocacy of progressive political action groups such as Greenpeace and Amnesty International.

In 2000, Anti-Flag was invited to participate in Vans Warped Tour. During this time, the members of Anti-Flag met NOFX's Fat Mike, owner of the Fat Wreck Chords record label. This meeting spawned a friendship that would lead to Anti-Flag's release of two albums on the label.  In 2001, Anti-Flag teamed with punk music producer Mass Giorgini to record the album Underground Network, released on Fat Wreck Chords. The release of the album is arguably the band's breakout from the hardcore underground to a more mainstream spotlight. The album continued to address the issues of fascism (specifically neo-Nazis infiltrating the "hardcore scene") and the United States' foreign policy. The album was the first to contain the now-commonplace booklet filled with essays from historians and political commentators, most notably Professor Howard Zinn. In February 2002, Anti-Flag released the album Mobilize on A-F Records. The album featured eight new studio tracks as well as eight live tracks of songs from other albums. In the wake of the September 11th terrorist attacks on the United States, Anti-Flag spoke out against the push for war with the album's title track "911 for peace". During this time, many music stores pulled Anti-Flag's records from shelves, as their music was labelled as "anti-American." In 2003, Anti-Flag released the album The Terror State on Fat Wreck Chords. The album primarily focused on criticizing the Bush Administration's handling of the War on Terrorism. Again, the album contained a booklet full of essays from the band as well as other political commentators. The album contains a song whose lyrics were originally written by Woody Guthrie entitled "Post-War Breakout." The track's music was arranged by the members of Anti-Flag, as Guthrie had never committed the arrangements to paper.  On October 8, 2004, U.S. Representative Jim McDermott gave a speech in the House of Representatives, praising Anti-Flag for their work in encouraging young people to register and vote.

Using a quote from the above article, answer the following question: When did they sign with them?
In 2000,