He's sent it to me, but there's nothing I can do past checking for the username on the forum.
If he doesn't have an account, I need his IP to do anything, and I can only get that if I'm in the room with him.
Edit: found him on the forum, banned him. He'll be back in a week, hopefully he learns. If he doesn't, then let me know, I'll talk to him and see if anything can be resolved. I can always ban him again, if it comes down to it.