They sometimes slip through the cracks. Most of my time on the site this week has been spent deleting spam (over a hundred articles in the past few days) and identifying and recording details of Steath Spammers for later action.
Most spammers use their account once and then create another later to use, so it is pointless banning them. Witness the 9000 or so spammers who are currently members but not currently spamming.
But, as you've noticed, some are persistent. I've sent a request to he Higher Powers to ban this and other recent miscreants, so hopefully their spammer days are numbered (at least until they sign up under another account - grrr).
> One of the best spam preventions I've seen is that people
> have to make a certain amount of posts before they can post a link to an
> off-site page. Could something like that be possible?
Spammers have devised a way to get around this - they use automated software that generates relevant messages (usually copied from other weightloss sites) to quickly post half a dozen on-topic messages within a few minutes of each other. You can see this has been done by a number of recent members - their messages reply to other posts that are years out of date, and have no real contextual content and often an odd signature containing their name or random text. Sooner or later they start inserting spam links in their messages or swap their plain text sig with a spam link. I've identified and marked these, and will delete their messages as soon as they start their spamming attacks,
Personally, I'd like to see a more aggressive anti-spam system in place - a combination of captchas for both signup and login, and some sort of active behaviour analysis of existing posts. But for the time being, us mods are probably doing fairly well given the limited resources. There's also the consideration that too many hurdles may dissuade legitimate visitors to join and participate. There are other forums out there that have been totally overwhelmed and ruined by spammers. Fortunately our little spot on the interweb is in much better shape than that.