Is there any way to report suspected cheaters on the PS3 version? The guy's PSN is "twitchedfingers" and he went 34-0 before my whole team talked on the mic and decided to quit. On 3 different occasions, my teammates or I were right behind him, shooting an entire clip, then knifing him from behind as he was occupied, shooting at another person. He took no visible damage (no blood or hit indicators) and he most certainly should have died.
I'm not even sure what type of cheat could make you completely invincible... Either way, how does one go about reporting it?