When we used to have a lot of problems with Hookton.com (the old version of the site) I used to spend time tracking some of these bots down. Sometimes if you google the user name you get literally hundreds of hits all on message board and all registered withing about half an hour.
There were some websites that had been adandoned by humans and were just packed full of spambots posting their nonsense. I came across one spambot that would post something fairly innocent and then another that was set to reply to it a few days later - and this was all over the place.
One day I even stumbled on spambots selling a program you can get to run spambots and from there I traced it to spambot central.
There were all these idiots on there comparing the best spamming software and posting ads to it. You'd swear the ads were for something highly useful.
Very strange people indeed.