Why not just implement a captcha feature for the comments and forums? Seems like a simple way to not only weed out the spammers, but would also get rid of some of the lazier and less useful comments. I think this is one of the few sites that exist that doesn't have such a filter.
It would also get rid of me. When you need to be able to explain and answer stuff fairly awesome, it would ruin the flow completely if you need to prove you are human every few minutes.
Seems like a simple way to not only weed out the spammers, but would also get rid of some of the lazier and less useful comments
People can spam too, you know. You don't have to be a robot to be a spammer. Any person who can type on the keyboard can spam. A CAPTCHA is usually nothing more than a series of letters that one must type before proceeding.
If you can read and you can type, you can spam. A CAPTCHA isn't going to solve that issue.