It's personal preference, I suppose. I tend to take the high road and it usually nets me better results. Generally if I retaliate I just confirm peoples feelings that multiboxers are cheaters and dickheads. When I ignore the behavior or respond in kindness the person usually will just go away and have occasionally apologized after a they think about it a bit.

I have 3 boys of my own, a 4th on the way in November, so I am well versed in this behavior. Immature people do crap like what this guy did to the OP to illicit a reaction and when they get it they are satisfied, for a time. But the next multiboxer they encounter they will act the same way to that person.

Crushing someone like a worm for being a prick is certainly within our grasp but I get more satisfaction from the possibility that I leave each player I encounter with the impression that multiboxers are in fact a different breed, but in a good way