I don't think he can do anything besides post spamming that is major. If it's automated registrations then you can add a mod to your forum that forces any new member to read a number of posts otherwise they'll get an error which does not allow them to go anywhere.
If it's human then there is nothing much you can do besides deleting the posts and banning him each time. I am sure he'll run out of emails to register with. Disable urls as well to discourage him from posting.
|