so far im sure people have found cheats. but, seeing that youre playing on a server with 64 people, if one person is cheating you prob wont even know let alone care.
also, there are things called stat padding, where you do certain things that dont involve actual cheating but are nonetheless considered so. for example, you get a point or something everytime you revive someone as a medic. so often, people will meet up, 2 from one team and 1 from another, and the one team guy will kill the other guy. the medic will revive. so the guy on the opp team gets two points for killing, then the medic gets points for revival. a lot of clans i guess do this on their own servers. ive never actually seen in being done.
supposedly a lot of that crap will change with the upcoming patch, and supposedly in the new patch to take a flag you have to get out of the helo (youll see what i mean when you get it).