Shouldn't you factor composite numbers? Factoring prime numbers is pointless.

You could make poisoned text extremely small, so it isn't visible to humans that percieve web page optically, but visible to crawlers.

Wouldn't Anubis notice that the an ip didn't finish pow check disconnected, and returned with different useragent?

So they can rotate IP too?

New youtube design eats a lot more memory than old. 250 mb is too big.