It's been a really long time since I created my account, but as I have been visiting at night, I find myself flagging a lot of spam that comes really quick. I'm sure this is not a unique experience for some of the people moderating spam here.
I'm not visiting as much as I used to, but actually I think it has slowed down a fair bit. A few months ago it was crazy. I was reporting several posts per day, and I know sometimes there was at least one more person doing the reporting at the same time I was doing it.
I get the feeling the spammers finally got tired of wasting resources.
Captcha is supposed to separate computers from humans by requiring potential forum members to do something that is too hard for computers to do successfully, like OCR scrambled and twisted text in a small amount of time.