How hard is it to hack World of Warcraft?

My friend keeps bragging about how easy it is for him to hack things even though he can't actually do half the crap he says he can... he is saying he could easily get GM commands and speed hacks on a REGULAR server not a private server and claims he would be able to get away with it all and GMs wouldn't detect his hacks, so back to the question. Is it easy to hack wow? Are there even hacks that work anymore with cataclysm? From my knowledge WoW is almost hackproof now.