I don't know which sites you visit, but I help to manage several lists on Google Groups, Yahoo! and other places, none of them use robots to manage new posters. Everyone new to the system is moderated.
It takes very little time. But we aren't on line permanently.
I am also a regular on several lists where the spam gets through. Some of them may use robots. It is then down to spammed users to report the crud.
Did you miss the bit about the weekend?
