Well, it looks like the comment spammers have won for the moment -- I've disabled comments temporarily.
They will be back subject to my implementation of a system that prevents it from happening again. Which I've been meaning to do for some time, but y'know -- those circular tuits don't generate themselves.
Removing the 90+ comments that occurred in a five-minute period was no fun at all to sort out -- but at least I managed to catch it before it hit ten times that number.