I was playing in a club tourney doubles match against a father and son team. Son was high school age. The son was stepping two or three feet into the court and serving bombs. I politely mentioned to the dad that his son was footfaulting and could he please ask him to tone it donw, and the guy almost came across the net at me. "He had never heard of such a thing, blah blah blah." The dad pouted the entire match, refused to shake my hand after we won and tried to give the impression I was a dick. I didn't know him and didn't really care. If the match had been close, I probably would have asked for the head pro to come over. I had to bite back telling the dad after the match he was really setting a great example for his son.