You'll find that BB apps have holes in them, or spammers figure out how to automate registrations and posts for particular systems.
Do a search on 'invision power board' (behind it.com) and you'll find bunches of sites using the same system, all of which can then be exploited with the same tricks. As holes get patched, the goofballs find new ways in and share them around. Bill has a full-time job on his hands, staying ahead of this crap.
Whatever you do, please don't CLICK on any of the links in the junk posts. It just encourages them. Replying to them probably won't make any difference though because it's doubtful that any human being responsible for the post ever looks at it again.
K