Darthdizor who is also well know as Purgatory was a group conqueror who used spam bots to gain members in his own private group Robot Factory, so that he could get an active large group going
by using this method. He has done much harm to really popular and active private groups as a group conqueror.
On an updated note: Darthdizor has lost control over Robot Factory and the original has been nuked. A new one has been created by an anonymous user so the name won't be taken again and that Robot Factory won't come back.