When you’ve become a celebrity for your music, you can often work as an advocate for change. These 12 musicians went to bat for their causes, taking on the government either in Washington D.C., their local chamber or on the road.

In 2000, Metallica drummer Lars Ulrich appeared before the Senate Judiciary Committee to present his argument against Napster and peer-to-peer downloading. “I don't have a problem with any artist voluntarily distributing his or her songs through any means the artist elects-- at no cost to the consumer, if that's what the artist wants,” Ulrich said during his testimony. “But just like a carpenter who crafts a table gets to decide whether to keep it, sell it or give it away , shouldn't we have the same options? My band authored the music which is Napster's lifeblood. We should decide what happens to it, not Napster -- a company with no rights in our recordings, which never invested a penny in Metallica's music or had anything to do with its creation. The choice has been taken away from us.”

When the PMRC was waging war against the rock and metal community, three musicians had the courage to address the government in person — Frank Zappa, John Denver and Twisted Sister’s Dee Snider. All three delivered compelling testimony supporting freedom of expression, fighting against censorship and the oppression of creativity.

Some rock stars have even run for office, with varied success. Dead Kennedys vocalist Jello Biafra unsuccessfully ran to be the mayor of San Francisco in 1979, with his platform mandating that businessmen had to wear clown suits within city limits. D.O.A.’s Joey ‘Shithead’ Keithley, however, won his election, becoming a city councilman in Burnaby, British Columbia, Canada.

Check out these 12 Times Musicians Took on the Government in the Loud List below.

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