Nickelback

Via www.wikipedia.org:

In 2004, Nickelback were playing at a heavy metal music festival in Portugal when the crowd started throwing debris at the stage. Front man Chad Kroeger put down his guitar and announced on the microphone, "Have we got any Nickelback fans in Portugal?" As this resulted in only a minimal positive response, he added, "Are you sure? Up to you. You guys wanna hear some rock 'n' roll or you wanna go home?" Kroeger then turned around and he was hit by an object in the back of the head, he then said "See you", before leaving the stage with the finger raised.

-Donovan