The biggest QQers in the game are chammers so never run up on someone who is hidden. You never know if he's doing the same thing to you. Some of them rage so hard they will SS and report you even if it means they will get banned too. When kill cam is turned on and you just sprayed someone turn around a corner you know nobody is hiding behind and spray there as if you weren't sure. That way at least 1 player on the other team "knows you don't cham."