Went to see it last night at AMC theatre in Framingham, MA
There was a Framingham town cop in attendance throughout the entire screening. He just stood by the exit... I've never seen a public cop standing guard inside a private business like that...
I didn't ask him why he was there... he was just doing his job, and it's tough enough w/o paranoid liberals accosting him. A lot of the folks who were there in the theatre were much more freaked out about it than I was. I think to some people viewing this film is a subversive act, and the police presence increased that impression for them.
The most logical answer is that he was there to make sure there weren't any interruptions, heckling, or other bad behaviour by Bush supporters or other riff-raff. Or he could have just wanted to see the movie, right?
I know some people were worried that he was there for more nefarious reasons, but what? Is he going to keep track of everyone there and then give them extra parking tickets? Report them to "seditionist central"?
It was still pretty unprecedented though, and it made me think about how a large number of moviegoers might be put off attending this movie if someone with a videocamera were recording them as they walked in...