"I'm a dog chasing cars. I wouldn't know what to do if I caught one. I just *do* things. I'm a wrench in the gears. I *hate* plans." - The Joker http://pressthenyckbutton.blogspot.com/
I really loathe Nickelback, but that's not cool. Under no circumstances should the audience throw shit at musicians or interact with them in any manner other than cheering or booing.
After Dimebag Darrell's murder, my opinion is only more galvanized. If you don't like the band, boo the shit out of them or leave.