If you think StarCraft II cheaters are ruining the fun for the more honest players, you'll be pleased to know Blizzard is cracking down on those no good jerks. And by cracking down, we mean they've got license* to ban. In a blog post on battle.net, Blizzard writes that if a player is found to be cheating, they'll be "permanently unable to log into his or her battle.net account."
"Blizzard Entertainment has always taken cheating in any form in Blizzard games very seriously, and that's no different for StarCraft II. If a StarCraft II player is found to be cheating or using hacks or modifications in any form, then as outlined in our end user license agreement, that player can be permanently banned from the game. This means that the player will be permanently unable to log in to Battle.net to play StarCraft II with his or her account.Playing StarCraft II legitimately means playing with an unaltered game client. Doing otherwise violates our policies for Battle.net, and it goes against the spirit of fair play that all of our games are based on. We strongly recommend that you avoid using any hacks, cheats, or exploits. Suspensions and bans of players that have used or start using cheats and hacks will begin in the near future."
*No, really, it's in the EULA.