A long time ago, I found myself in a subway station, noticing a gang of about 8 teens working themselves up to do a beating on this effeminate little guy. I walked over and just stared at them. Never said a word, but my hand was on the knife in my coat pocket
They talked some s**t for a while, but finally left. As a group, they could be sure they could take me. As individuals, they could be certain that I would kill the first one to come within reach of me.
Nobody wanted to be first.