Forum Being Hammered with Mobile Phone Spam
 

My VB 3.8.4 forum is really being hit hard by mobile phone spam over the last week or so. These spam posts are along the lines of, " FS: Brand New BlackBerry Bold 9700 @ Affordable Prices"

My forum's spam protection is quite good, but these mobile phone ads appear to be getting through. I issue a permanent forum and IP ban on everyone one of them, but they keep coming.

Any suggestions on how to stop this?

Thanks!