Feuerstein

my brother (ex-officer, marines) was coming out of a hardware store when he saw the guy breaking into his car. He didn't shout at him or give any other warning, just walked calmly over and beat the guy to a bloody mess with a crowbar he had bought in the hardware store. Fortunately the police displayed an amazing lack of interest in investigating a self-provoked assault on a known repeat offender, so despite a large number of witnesses, no charges were pressed.

I caught a guy keying my old 100, managed to take him by surprise and beat him to the ground - but then I stopped, I see no point in hurting people after they surrender.