Lately I have been noticing on the various forums I administrate, that spam has been increasing big time.  I have basically every tool available to prevent bots from spamming, but more and more it seems as though actual people are creating dozens of accounts at the most popular forums, and spamming all sorts of content.  The best thing to do is ban the ip ranges these people are using and be persistant.  If you are persistant in removing their Forum Spam, they will likely get tired and move on to other forums which are not as on top of things.  A Good moderator staff is key to the success of any forum.