one of our most intimidating looking safety officers was just in here. to ask me loudly "Were you having a problem of any sort that I can help you with?"
Someone hit the emergency call box button near here. Standard procedure if I have to scramble is to hit that box. (I didn't hit it, some yahoo either accidentally or intentionally bumped it)
Side effect, though, is that students are now sitting quietly, theyv'e shushed their cell phones, and are looking meek.