Thanks for letting us know. We have put a few measures in place to combat spam (keyword filters, moderation of documents, etc.) but the buggers find a way to get around it. We have taken out these guys and the offending content, and will continue to work to eliminate spam here in the Community.
As a help to us, if you see spam, please click the "Report Abuse" button in the Actions menu to the right; this will throw it into moderation and flag it for our review.