ACR Multiplayer cheating??

I play a lot of multiplayer and something that I have noticed lately is really starting to piss me off, I don't know if it is a bug or cheating, so I wanted to ask your thoughts.

First thing, smoke bombs. I have noticed certain players "ability" to either walk right through my smoke bomb and either kill me or stun me. Today not only did this guy walk through it, when I tried to poison he jumped out of the way. I ended up killing him with a contested kill but still...He then got on his microphone and taunted me about my smoke bomb. He then quit out. Is this possible cheating? Or is it some ability I am not aware of? Second is Animus Hack. Had a really aggressive jerk off who was annoyed with me because I was winning. Kept following me around and throwing smoke bombs at me. Anyways, all of a sudden EVERY SINGLE PLAYER DIED from this ass hats Animus Hack. Can you kill everyone???? I am reaching a breaking point, if it's cheating I am going to quit, go back to Brotherhood. If it's legit, well that sucks.