Game Center hacked... Apple does nothing. Why?

Hi everyone. I've been using an iPad for just 1 month so I'm kind of new to it and to all the Apple world, but there is one thing that I have already crearly noticed... The Apple Game Center is hacked in so many games (Angry Birds, Cut The Rope, etc...). I mean, the first players of the rankings have like millions and millions of points, way more than the max total of points you can win in those games. My question is simple, why doesn't Apple ban those cheaters for ever like Microsoft does on XBOX LIVE or Sony does on PSN? It just seams like Apple doesn't really care!