Every fan has been to a concert and shook their head in disbelief as someone falls over drunk, gets tackled trying to rush on stage or does some other crazy action. Well guess what – artists see that stuff too. We spoke to 11 top acts about the craziest things they've ever seen a fan do at one of their shows. The results ran from the comical, like the 10-foot tree that wrestled Moby to the stage in Toronto, to the eerie, like the delusional Alice Cooper fan that convinced her father she was Evanescene's Amy Lee. —as told to Steve Baltin