[Adam Harley (Kawauso)]

I’ve found running SABRE with stealth mode on in WordPress stops 100% of our bot registrations and I just point bbPress at that. If you disable registration with either .htaccess or changing the function, it’ll put a complete stop to any registrations on the bbPress side, so you shouldn’t need any spam protection besides that unless you let unregistered users post. bbPress comes with Askimet installed anyway though.