I know this is a little late, but I thought your comment about sacrificing bunnies was cute and terrible at the same time. I am so confused! Bunnies are so adorable.
Oh, and yeah anything you can do to get rid of bots would be appreciated. I don't understand why they do it - I doubt anyone ever clicks on the link. I know some forums won't let you put in a link until you have a certain number of posts. Also, in case you aren't using it already, SMF makes a mod that checks registrations against a database of known spammers.