In the time that I was gone (See: Laptops don't like water) the forum has accumulated an impressive amount of advertising bots/people. They never get around to posting any garbage, but they are certainly sitting on the user names. I will be doing periodic cleanups of these users by deleting their accounts. If you know someone who got deleted, tell them if they aren't going to participate, don't sign up at all. If you introduce yourself, you will most likely be spared.

The best way to clean them up is the Prune Users option in the admin panel. I generally ban the IP and then do the prune option. I also check the Delete User and Delete Posts options. That way it compleatly removes thier junk from the forums.

Prune Users? I tend to just go to Manage Users on the ACP and delete them one by one. And I do IP bans and email bans if they are blatant advertisers. If they have no posts and no info, I just delete the account.

Prune will remove the user and any post that they have done.
What I usually do it open thier profile in one tab and then click "banning" to ban them.
Then in another tab I open the admin panel, and run the prune user thing.

lol. I just did a email ban on all know junk accounts, to slow down the junk.

Hope that helps a little bit.