Any way to prune spammers from usergroup?

[mrfarb]

As the title suggest, there are a lot of registrations in my forum that could possibly be spammers. I delete the new registrations that have spam links, but what about the ones that are "dormant" for lack of a better term? There has to be some bots that got signed up but never were active.

I guess what I'm asking, is there a mod that will search your member database for known spammer IP's or Usernames? Just curious.