On my previous post on comment spam Phil made a good point, that since I generally close comment threads once spam appears (because I can't afford to be removing comments and rebuilding too often) it makes for a Godwin's Law sort-of-thing, where someone could essentially "engineer" the closing of a thread by posting spam.

I hadn't thought of that! I can say though, that generally when I get comment spam posted I also ban the originating IP, so whoever did it will have problems posting in the future (and the IP should also let me see if a spam looks iffy by being the same as someone who just posted a comment). For people with dynamic IPs (most of us?) it won't necessarily work, and someone could re-login (to their DSL, etc) purposefully to try to change IPs... I guess it's not a perfect solution, but it's good enough under the circumstances...