Some of those "public photography" guys are annoying. In one instance, a guy was just standing around looking suspicious with a camera in front of the DEA office building. That just doesn't seem that bright or reasonably respectful--consider that many of those guys going in and out are under cover and wonder if you might be someone who is trying to blow their cover or put a hit out on them.

At the same time, the general paranoia in public is a bit silly.