This problem could addressed in an automated way by allowing accounts with fewer than 100 posts to only start 1 new thread per hour. The spammer could create lots of new accounts, but at least it would slow him down, and he would get tired of doing it more quickly. Last night he was left to his own devices for over 2 hours and filled every subforum with pages and pages of spam threads. I believe he only quit when he finally got bored or tired.