Banned because I didn't need to go to Greece to tell you that.
Personally, I think that the main reasons for police brutality are poor judgement of the character of recruits, a refusal to deal with it, and, in Britain at least, a lack of appropiate equipment.
Who thought a baton was a good idea? Sure, it theoretically is less likely to kill you than, say, a gun, but you're not going to stop beating the crap out of a guy who's assaulting you with a knife or something to check that he's still breathing.