People register with fake emails because, they themselves, do not want to be spammed. I do it myself a lot. Antispam questions actually are pretty effective. Not many spammers from .cn .tw .ru ...etc, know the name of the longest river in the US, or are willing to take the time to look it up.
Captcha is only useful in blocking registrations by spam bots.
Captcha is only useful in blocking registrations by spam bots.