No... this has nothing to do with privacy. People want the achievements added to their profiles, and are cheating to add them. Why this matters to anyone, I don't know, as the most "useful" items you get from StarCraft 2 achievements are avatar icons and logos which can be placed on your units, logos which are so small I'd swear you'd never see them in a serious game. And SC2 has cheats built in, that disable achievements, so if someone just wants to see the story, they can easily do that. The only reason to cheat with hacks is to either get achievements that one is not good enough to earn legitimately, or to cheat in multiplayer.
Microsoft has had similar problems with their achievement system being cheated as well. Their answer has been deleting all achievements from the people found to be cheating in this way. Banning someone from the game does seem a little harsh in this situation.