Ah, crap, that didn't last long. 5 new ones today, just without a website or signature. I considered asking about extending the mod to include other fields like ICQ, location, occupation and interests, since none of them are actually needed during registration, but one of the bots didn't fill in any of them, so it would have still got through.
Actually, I have a mod that does that already if you are interested. 8)
It is quite a bit more complex though(adminCP interface and everything).
I am hoping to get a chance to update the Anti-Spam ACP this week. I have a few bigger things I wanted to change.