I'm not much of an admin - I'm just here to strike fear into the hearts of particular users. It's a dirty job, but somebody has to do it.
We've debated pre-emptively banning people before based on criteria like that. But for whatever reason, we don't take the time to search IP addresses. First, it's time consuming. Second, we already make use of anti-spam features in vBulletin, which have cut a lot of the nonsense out. Third, IP addresses get recycled so we are probably penalizing innocent people who are unlucky enough to pick up a banned IP address years later.
The better solution is to resist the urge to be continuously helpful and not reply to potential spam. There is a 'report post' button on the header of each post that can be used to alert moderators to a potentially fishy post. It sends all of us an email. From there we can look at the user history and the post and determine whether a ban is in order or not.
Normally this entire thread would have been gone as soon as I spotted the garbage and people replying to it. But I'd like to give everybody a chance to learn to spot this garbage and to read how to report it correctly.
Mike