It's a sad commentary on the general decline of common consideration for other people that what used to be acting like you have some sense now seems to require police presence.
That was interesting a few posts above about how stadium staff have authority over the police. Nevertheless, standing the whole damn game, essentially giving the finger to people behind you that have to look at your butt instead of at the field, is a sign of juvenile, self-centered, generally boorish behavior. I swear that some people act as if they were brought up in a barn.
If you want to stand for an extended length of time, mosey on up to the top of your section and join the other standers. It's not like you're using your seat for anything anyway. I've done this. They're nice folks up there.