I've seen things that I've often thought were wall hack, but honestly with this game it's just the lag. I can empty an entire clip at a guy and then get one-shotted only to watch on his kill cam that I never even fired a shot. If you are on the wrong side of lag you can be 1-2 seconds behind everybody else which means you are basically dead.

However from time to time I do notice odd things like a guy will be sniping in a building and I'm coming from the opposite direction and he suddenly just magically switches to secondary and runs to the other window and shoots me in the face like he had eyes in the back of his head.

you know this how? Just curious

What about someone with akimbo sileneced desert eagles or having kick but still having two  attachments are those just cheats not hacks?