I enjoy seeing nerds get butt-hurt, and enlisting the use of cheats designed just to get achievements (I haven't played SC2 but I assume there's certain cheats in the game that make the game easier etc.) sounds like one of the saddest forms of cheating. Deactivating someone's copy of the game may be a little bit harsh, but at the end of the day if you don't cheat (or simply stick to cheating via the allowed means) then you won't have the hand of Blizzard come crashing down upon you. Read the rules and don't complain when you get caught breaking them.