Generally what happens in that case is mutually assured pwnage. The more people troll him the more hes going to forget with everyone else. Granted that he's going to do it anyway but this entire ordeal isn't really helping. I'm not talking about morals/whatever, just voicing my opinion about the witch-hunt.
I personally would not do anything with the information
I just want it
even if I cared enough to do anything, I wouldn't know where to start
so revenge isn't entirely the point for me