I'll weigh in on this. As a Admin myself I have to rely on my Mods to nail the spammers. I use about 5 active Mods that are in different time zones so I have good coverage. I also had a programmer offer to make a script to alert(pm) the Admins and Mods if someone posted a set number of posts in a period of time that is used. <My site uses the forumotion software> Banning of the user, IP, or even a IP range ban may have to ensue.(in that order if required, IP range ban was a last resort)