I installed a new tool to find spammers on another forum I run (I may convert this one to the same software after what I found).
Everyone hates Captcha and such, however, even with all the common anti-spam system, this is a screenshot from one of my other forums memberlist. This forum has used email verification, question and answer and Captcha, since day one, and a post verifier for half it's short life.
Sadly, the screenshot wasn't even the worst page, the worst had only ONE legitimate account, the rest were all known spammers. In the end, that forum went from 55 pages of users, to 19. Almost 2/3rds of accounts were fake. Again, these are the ones who got through. In the 2 hours I worked on the site, the system blocked another 200 attempts.
While we hate it when we see it, the spam you guys actually see, is just a grain of sand on the beach compared to how much these systems stop, and they are always looking for another loophole.