Something weird's going on with comments. I didn't change anything, and I doubt Catherine did. Nothing looks wrong in the settings. Angry emails have been sent to our webhost. I'll keep you posted.

UPDATE: Scratch that. Looks like the word "NMAP" somehow got onto our commentspam blacklist, and the error page that's responsible for letting users know their comment looks spammy is missing, generating a frightening-looking error. If you aren't posting a comment about that particular port scanning tool, you should be fine.