You did the right thing, DP. We had to do something similiar on the LDRiders list a while back. Some of us learned that one of our more vocal (abusive) members on the list was a convicted child molester and con man who beat women. In spite of his threats of violence, we HAD to stand up to him and tell everyone on the list about him. You see, we ride thousands of miles to meet with each other and stay at each others' homes. We just couldn't stand by while there was a chance that this puke might molest some riders' teenage daughter or wife. The last straw was when he threatened one member's family. This after helping get the guy a job there in the first place to try and help him turn his life around.
He's been driven off the list but we are continuing to get harrassed by him via email impersonations which we cannot prove. But, what we've done to retaliate is to post public information bulletins about his arrest record on web pages. Each time someone harrasses us, we assume it's him and add another bulletin to the web page, along with telling him that we're doing it and asking that he stop his harrassment. It's worked. We haven't been bothered in a couple of months now.
Your situation is probably alot different in that this BrainO character probably doesn't have a rap sheet a mile long like our character did. But, it's best to be safe with these jerks.
Be wary, he may come back under another alias and be more careful. You might want to arm yourself with more information about his REAL name, etc. - just in case.
Good luck,
Joe Zulaski