There is a script you can use to modify the database so that registrations have to take at least 20 seconds. If that was used, no spambots would be able to register.
Or, maybe just make people post at least 20 times in various threads before being able to start their own. I think that would keep some people away, as it'd take time to actually get 20 posts, or whatever it was made. Then again, it could increase spam, but maybe it's worth a shot?
Wouldn't the spammers just post their spam into existing threads then? That would make it harder to remove.
Yes just as big Mike put it, It will be scattered threwoutht individual threads. It happens periodically as it is but such an action would only make it worse. http://thephotoforum.com/forum/showthread.php?t=93605
well i have ran and maintained lots of forums. One little trick that seems to work for me was to include a common sense question in the registration form. I uses phpbb not vbulletin so idk if you could do that here. It would be a basic question like How many legs does a donkey have? and the correct answer would be 4. Spambots dont use the registration form to register, they just use the 4 basic info needed username password e-mail and the picture confirmation code they can break sometimes. but if you'd throw in a 5th required logic question they wont be able to register. Just my 2cents, its worked for me in the past.