As part of my continuing battle against comment, trackback, and feedback spam on this site, I've instituted captchas against anonymous users. Unfortunately while the spam module for Drupal did a decent enough job of getting rid of comment spam, it hadn't done enough to stop trackback spam and absolutely nothing for feedback spam. Blocking two IP ranges from which most of it came certainly helped but the problem is returning.

Sorry if you don't like captchas. I know that they can be defeated somewhat easily by training spam programs, but it's one more hurdle against the spammers. I don't want to disallow anonymous input entirely, but it is on the table. I hate spam, and I'll do what I must to keep it off my site.