On Tue, Jul 17, 2012 at 1:34 PM, Neil C Smith <neil@neilcsmith.net> wrote:

Hi,

I'm involved with the management of a range of sites and we find that
even requiring registration and an email address doesn't necessarily
cut out all spam. You might also want to consider something like
Mollom (http://mollom.com) - it's free for small community sites, and
developed by the originator of Drupal.

mollum didn't work that well for ardour.org. we eventually turned it off. i nuke spam (and its creators) by hand.

the best suggestion i've seen was something on a boingboing comment thread where user registration involves answering several human-ish questions correctly and then filling in a free-form answer "why do you want to join?" a few idiots actually write "seo" in there. with a relatively low sign up rate, this can be easily human-managed, and avoids 99.8% of all spam.