Well i think that this sort of behavior is still frowned upon. You wont get kicked out for it (or for really doing anything else) but people tend to stay away from you after.

One thing I really enjoy about going to metal shows is the crowd. We have the most violent sounding music on earth, yet the fans / scene is almost always completely peaceful and friendly. I made a bunch of new friends simply by being there. You can get into a fight by accident just by looking at the wrong person at most shows... Something peaceful like country music.