mojo pixy
...שלא נמצא בשמאל
I've never been to a really big gig like eg. Nikki Manaj. Maybe that's where most of the bad behaviour is. People there just to say they were there or have a night out.
Funnily enough at the gigs where you might expect a bit of a rough ride (punk, metal etc) people tend beyond that to be quite reasonable and friendly to each other, even factoring in the drinking. And real knobheads get dealt with pretty quickly. Same at raves really. Maybe that's just an in-group thing and the bigger the gig = the wider the appeal = the more knobheads.