Worst encounter with a customer?

A while ago I had a table – a couple of guys – who just walked out without paying. I chased them out of the restaurant but couldn’t really do anything about it. Another time a drunk customer had an altercation with my manager and spat in his face. The manager pressed charges and, as I was a witness, I ended up going to court. Another time, I served a large table and when I gave them the bill they basically claimed they had already paid. So the manager went over to the table and the customers made out that I had charged them twice. So humiliating. Most of the problems in the restaurant stem from the bar. There have been some fights between customers. It’s gone as far as the police being called. I don’t think anyone’s actually been bottled (so far).