Original: Rock On The Net : Green Day Green Day 's 2004 rock opera American Idiot reignited the band 's popularity with a younger generation , selling five million copies in the U.S. . The band 's eighth studio album , 21st Century Breakdown , was released on May 15 , 2009 .
Simplified: Rock On The Net : Green Day Green Day 's 2004 rock opera American Idiot sold five million copies in the United States .