Pantsing and Stripping Forums

Enable some form of questions/answer based thing during the sign up process. Add about 5-10 different questions to this and change the pool semi-regularly. Bonus if one of the questions is "not politically correct" which may prevent the AI from being able to answer it. For example, any references ...

Oh, I have been doing that, constantly in fact, another element that makes me think this person is doing this by hand, because it'd be easy to just use a VPN to switch to a new IP address.

Well, one of the new anti-spam countermeasures seems to be working, so at the very least the spammer won't have an easy time getting around it.