I just spent three hours deleting spam on Tabulas. This is a losing battle. I cleaned up tagboards and comments, and made stricter captcha checking (the spammers were getting around captcha checks by avoiding putting links in the content of the comment, now all guest commenters have to pass a simple captcha test). It's only a matter of time before the spammers start OCRing the text... and thus it goes on.

Some changes I've made:

• Tagboards now support IP banning. I don't think this will help, because most spammers are submitting false IP addresses with every post
• I've added a noindex attribute on the page, which means search engines will stop picking up those pages; hopefully removing the google pagerank incentive will do something to stem that tide

I can continue to spend time building more advanced comment tools, but I think the long-run, there's only two real possible solutions (both which I may pursue in tandem):

• Start passing all comments and tagboard entries through akismet, which is an automated spam filter service provided by the fine folks who work on Wordpress. The only downside here is that it's very expensive (200,000 calls is $200/month, which means every 1000 comments costs me $1). I'm thinking I could implement it just for guest commenting, which may be a good short-term stopgap solution. This wouldn't include tagboards, which would still pose a problem.
• Hire somebody to start filtering through the comments/tagboard entries by guest posters manually. Costly, but probably the most effective way of getting things done

For the time being, I'm going to continue to develop internal tools to battle spam; by being really vigilant and being timely with deleting spam, I'm hoping I can simply discourage spammers. It's that whole "Fixing Broken Windows theory...