I was at a Black Crowes show years ago when some punks started that "mosh pit"crap.The singer ,Chris Robinson,stop the song and politely asked the idiots to stop it and give everyone else some consideration that wanted to enjoy the show.When they wouldn't stop he stopped the song again and cussed them out down one side and up the other and threatened to have them all thrown out.I always thought that moshing was ignorant anyway and anyone that does it gets what they deserve if they get all busted up.
Ive been to a couple of small Punk Rock shows (few dozen people at most) as an observer (a friend of mine was playing in one of the bands) and the activity has great potential for injury. The people running those kept it under control by hustling out anyone who got too violent, but I could see how hard that could be in much larger settings/crowds.
Funny, I have only a faint idea of the music because I was wearing earplugs the whole time (my ears physically hurt the first time I got just inside the doorway without them in).