Spammer Tar Pit Plugin
If you have any IP numbers listed in your moderation_keys setting (thatâ€™s where you put the spam words in the Comment Moderation setting under Discussion Options), this plugin will check them against the current visitorâ€™s IP number. If it matches, the visitor will get a delay (thatâ€™s the tar pit â€“ it slows them down), then an â€œAccess Deniedâ€? message. You can customize the delay time and the message of course. Advanced users can also add additional IP matches manually, should they so desire. You might want to do that in order to match against an entire IP block, for instance.
This works great in conjunction with Kittenâ€™s Spam Words Plugin. Anytime you â€œDelete comment as spam", the offenderâ€™s IP number will automatically be added to your moderation_keys.