Green Day singer trashes Justin Bieber during Las Vegas concert

Green Day singer Billie Joe Armstrong interrupted his band's set in a Sin City concert Friday night when organizers informed him he only had 1 minute left in their performance. Armstrong decided to insult Justin Bieber during his tirade.

Armstrong and Green Day were playing at the iHeart Radio Festival in at the MGM Grand theater in Vegas when told they'd have to cut their set by 20 minutes. There were other bands to play and though Justin Bieber was not up next, nor even on the concert bill or in Las Vegas, the punker decided to go off on the Canadian teen. “I’m not f------ Justin Bieber, you motherf------!” Armstrong screamed. There was a connection to Bieber as the next act was Usher - makes sense, a punk band followed by an r&b pop artist - who is of course a mentor to Bieber, and has been influential in the 18-year-old's career. Other acts at the festival included Rihanna, Brad Paisley, Bon Jovi, Aerosmith and Taylor Swift. Armstrong, who also did some ranting about how long Green Day has been around (1988) and some smashing of his guitar, is also in a band called Pinhead Gunpowder; which somehow sounds appropriate.