in the hallways, classrooms, and common areas, no problems. It's a lot easier to hand the camera to the police than go through forms, questions, etc. The students film just about everything with camera phones, so this is a way to get my own documentation (my camera phone isn't that good, and what they're filming I'm either breaking up or calling for backup--fights, sexual misconduct, tagging (vandalism), smoking, etc.)
In the bathroom, no;