Moderator: Inner Sanctum
Having a site forum has the potential to be a powerful way to open up your site to traffic of the desirable sort, however, the general trend is for a large amount of the undesirable ilk, specifically bots. This conundrum affects Wikis, bbPress, BuddyPress and other social installations as well. Of course, you can disable registration alltogether, which defeats the purpose of having an 'open discussion' site, but one of the most effective methods of controlling registration is to allow new registration by administrator approval only.
Any input on this topic would be appreciated!