Billy Joe Armstrong is the lead singer/guitarist of the "punk" band Green Day. Billy Joe was formerly a libertarian and is still a registered libertarian. Previous to "American Idiot" few of his songs had political messages, and those that did could be viewed as either liberal or libertarian. Several songs that he wrote dealt with his enjoyment of illegal drugs, but he has never made a case for drug legalization. His most libertarian song would be "Warning" from the album of the same name. The song poked fun at the stupid warning labels that the government forces companies to put on their products, amongst other things. Another song "Minority" also contained libertarian undertones with lyrics such as: I want to be the minority/ I don't need your authority/ Down with the moral majority/ 'Cause I want to be the minority

In 2004 Green Day released their most ambitious album to date "American Idiot" a supposed punk-rock opera, the band gained success they had never dreamed of. However, the album drew the ire of the punk community and few would still consider them punk. The album contained left wing (mostly antiwar) lyrics that could be considered libertarian however, Billy Joe's active support of John Kerry during the 2004 election cleared up any misconceptions that he was still a libertarian. That said Billy Joe has never written a song that directly contridicts libertarian philosophy.