About a year and a half ago (mods, please correct me if I'm incorrect on the time), John Hammell, the site administrator, blocked unregistered users from posting.
Unfortunately, that decision didn't put an end to ridiculous posters who seem to invade the boards from time to time.
ZTA, I see what you mean. I've been gone for a few days, and I see where intelligent discussions are invaded by those who just feel the need to get their clown on.