I was at an Iggy Pop show in the early eighties when the audience asbsolutely pelted the stage with their drinks as soon as Iggy came on.
He played about half of the first tune before flipping off the crowd and leaving. I would have been pissed also, because it was not the occasional drink flying towards the stage, but a barrage.
Iggy came back to the stage after several minutes and finished a good show. Most of the audience managed to hold on to their drinks as well!
