You get them everywhere

Knoppig (22k?) disputed a pair of dead stones (B10 and C10 in the image) because, although they were surrounded with no chance of life, I hadn't bothered killing them off despite the fact that he passed his last move. He quickly reversed my removals and ended the match resulting in a win for him by 1.5 moku. He's ignored my two requests for a rematch since.

Up until now, everyone that I've played against has been polite, courteous, and fun. Rude folks are everywhere. I hope the likes of Knoppig are in the minority.