I have yet to see a crowd in the states behave like that, even as drunk as they get!!
How many races in the states have you been to that you get to be that close to a race car? That might explain why you dont see it as often... I'd like to know so I can attend some of them until I get my passport and can go to Mexico again
I'm not by any means defending these morons, only times I've been in baja surrounded by a mob like that we got helped (granted one of those times I was in the car with Carlos Iribe and he knew how to ask for help)
I've never seen anything like that in person, but the times I've been in "mobs" like this we were there to help the racer.