Forums spam has really become a problem. For example, Google “OST Recovery” and look at all the crap posts that come up from everywhere. Over at PowerShell.org, we’ve been dealing with exactly those jerks – and we’ve recently come across a great weapon.
CleanTalk is a WordPress plugin that works in conjunction with WordPress’ own “Askimet” spam filter. CleanTalk is a bunch more aggressive, using a combination of heuristics and a blacklist to stop registrations of known spammers, as well as to stop suspicious-looking posts. A huge bonus is that it doesn’t add more CAPTCHAS or hurdles for legitimate users. Instead, when it wants to block something, it just does it – and displays something on-site so the affected user knows what happened. We’ve had remarkably few false positives since implementing it, and our spam rate has gone down to almost zero. It’s been a huge help – and if you run a site that can benefit from it, it gets my total thumbs-up.