I heavily modified the other site, so there were several hoops to go through. e.g. removing what version of the software it was, adding captcha to signups, min 5 or 10 posts before links can be posted, some back-end stuff linking to stopforumspam, I think there might be a honeypot on there, and obviously the great work there from the mods. There was a time when there was about 50 spam messages a day, all manually cleaned up. That's when I had to get stuck in to do as much automated prevention as possible.