How about this one, happened to me yesterday: I'm taking the elevator in my building, dude gets in, he's a stranger and there's no eye contact. Just him and me in the elevator. He lets out a rolling belch, clearly disrespecting me. He's also bigger than me, and of a different race. Could have neck punched him right there. But what are you going to do?
Dr Johnson rumbles with the RawGod. And lives to regret it.