Green Day's Billie Joe Checks Into Rehab for Substance Abuse

Green Day frontman Billie Joe Armstrong has checked into rehab to get treatment for substance abuse. This comes two days after the 40-year-old rocker went ballistic on stage screaming obscenities, smashing his guitar after his band's set was cut-short for RnB star Usher at the iHeartRadio festival in Las Vegas.

Since breaking into the limelight in 1994 with their album 'Dookie,' Green Day has sold over 65 million records worldwide.