Drop to DOS, Pipe + pie = 3.142 x e144 squared takes you to the gate, type in the member's name +fe = forever and they can never post to your threads, it will just go whoosh when they try. Moderators will not be able to fix it, neither will Admin. It would cost too much to find someone knowledgeable to fix it.
Try it with me - as your first memeber to block forever. That is why even at ET I never needed the Ignore button. Problem with Ignore is that you are then an ostrich but your bum sticking out and the attempted to be ignored person and come and stick a didlo in your bum. Ouch!. so you want a full frontal confront like a MAN - kinda difficult here and far=-fetched.
The advantage of this is that mnobody else can see their posts in your thread either so there is no debris.