Haven't seen any issues since I enabled ReCaptcha. Lucky us!

I don't think there's really any issue with the forums themselves, just considering the popularity with little spam protection is going to attract lots of spambots- especially since this place doesn't have real registrations for most of the year.

Ideally we should clear the members database and come up with a good strategy for spam at some point since most registrations are spambots and that'll make the place a lot cleaner, but we definitely can't do that right now :p