Interesting solution to comment spam

This is a pretty interesting solution to the problem with comment spam. Really clean and neat: comment spammers are like migrating pigeons, they land on your blog, crap all over it, then disappear, so by only letting IP addresses that have visited before post comments, you get a really nice first line of defense. The system will probably have to be tweaked a bit once the Evil Vermin figure it out and start visiting once, then waiting a few hours before coming back with their guano, but some judicious algorithm tweaks might help keep that problem at bay.

Sad, though, that smart people are having to waste their time combatting what shouldn’t be a problem at all.