If someone is using a blatant aimbot then it is rather easy to know in-game. I agree though that a lot of times people will think someone is cheating when they aren't.
i didn't come here to cry cheat cos i got beaten, i said it cos it was a fact that i saw 4 different people, 2 of which admitted it then when on opposite sides proceeded to clear out the server.
no im not a bitter twisted loser, no as the other guy said, they died too frequently from behind, they had no skill, just the amazing ability to track through walls at decent ranges, consistently wallshoot.
I too frequently get accused of cheating. Getting a 9 kill streak instantly makes you a cheater/camper/hacker in blops. I pulled 5 games in a row with 40+ kills and had 12 people accusing me, fact is they were all crap, and i was playing well.
we have all played FPS for years, me personally for 14 , i think we can tell the difference between talented players and average players with assistance.
So i dont claim to be an authority on spotting cheats but i have a strong gut feeling with players that seem to good to be true.
ps this isn't a direct reply to you DD just quoted you.