Sounds like negative SEO. I remember reading about one particular spam tool "XRumer" which would register fake forum posts and run amok spamming for SEO backlinks. Google caught up and running xrumer became almost a guarantee for being de-listed. Of course, the logical conclusion to all this is bad guys turning the tool against their competitors. A random story from googling xrumer negative seo is this story about blackmail threatening to spam the victim's URL: http://www.warriorforum.com/search-engine-optimization/11499...
