My blog has been getting a lot of comment spam which has been tedious to try to resolve. I am using several anti-spam Drupal modules and these catch a lot of spam but about 10 spam messages were still getting through per day. It got so bad that I completely disabled comments on my site but this was clearly not a good solution. So I have changed the permissions so users must log into my site before you can post comments. You can register a new account on this site or you can log in using Facebook, Google or Twitter (achieved using the Drupal HybridAuth plugin).