I can't be the only one who sees this is true. If you leave a forum up that's dead, someone is going to post in it. Considering that someone is almost certainly not going to be from the place, all you have is spam. So try and explain to me how keeping a dead forum up just so you can tell people not to post spam in it is somehow worth your time and the bandwidth? And no, bandwidth isn't a crucial issue, but that doesn't mean you have to waste it lest it become an issue.