Account creation is disabled on this wiki so we don't have any spam-fighting overhead.
These people have the required god powers to create new accounts. Track em down.
Ideally folks could create their own accounts from the Skullspace network. As far as we can tell media wiki itself doesn't have the ability to be restricted in this manner. Trying to do this by restricting just the relevant page from Apache seems like a bad idea.
It would be nice if we had a simple, separate web application for account claiming that we could restrict at the web server level. If you're interested in working on such a project, contact firstname.lastname@example.org.