All,
I'm working on tightening things up to stop the torrential influx of spam. The process needs to be refined a bit.
Thanks for your patience as we continue to address this.
Dave
It often helps if you are forced to supply a valid email address and can't activate your account without clicking a magic link you get sent out to the email address you supplied.
This also helps later when trying to blacklist people - you block the account and block that email address from creating a new account.
People who run own mail servers can create an infinite number of email addresses but in that case it's possible to blacklist the whole email domain.