Joomla! Discussion Forums

The way i handled the situation for the bots was to simply use the SMF registration/login module (through the SMF bridge) + Advanced captca modification. Also you need to edit any links that refer to the joomla login module or simply completely disable it in order the bots not to find it in your site and start registering again. Image verification + email activation did the trick though although the bots still attack every day and mess up the site statistics damn it!

Joomla should have embedded image verification at the login module in the future because it doesn't mean that everybody uses SMF

We (Joomla! Forums) have the default SMF image verification on use for new users. New users also need to activate their account before they can post, and then all users have a minimum of 5 posts before they can send PM's. However, we manually catch a few spammers each day and delete their posts and then ban them.