Theyve also mentioned multiple times, including at gdc, that the worst thing that can happen to a game (and therefore its profits) is having negative sentiment grow to a degree where people go around telling other people not to play the game. Doing nothing about cheating is a quick way to have that happen, which is why they HAVE been doing things about cheating. The problem is that cheats constantly evolve, and if they were at all transparent about what theyre doing to try and stop it, then it would be easier to develop better cheats. The only reason it feels like theyre doing nothing is that the more information we get about what specifically theyre doing, the less secure the game gets. So they tell us as little as possible.