I'm looking through the log file which records the attempts of account registration and I can't believe how many attempts to create accounts are rejected.
Between:
2011-02-13 16:21:55 & 2011-02-14 11:26:44 there are 200 attempts to register accounts from spammers. The plug-in I'm using rejects them based on look-ups from multiple sources. Of the 200, 3-4 accounts got registered and one made a post that was automatically moderated due to the content. The other accounts register and put spam links in their profile.
They are persistent fucks.
Also, since I've implemented this, there are 17,197 total log entries (each log entry is an attempt to register an account). I started using this on 2010-11-07 09:08:16...