Criminal usage of sharing services is potentially an enormous problem.  He got off lightly with realizing his disclosure risks only through stalking.<p>Using only a few services a criminal could potentially have access to personal information that would aid in guessing common security prompts (Facebook,  etc), lists of purchases or photos of your possessions (Blippy, Facebook, Flickr, etc), and your physical location and/or travel plans (Twitter and numerous others).<p>I think the anonymity we perceive from the fact that our disclosure is not person to person is a cognitive misconception.  Realistically, we are walking around and publicly saying these bits of information.  Something about telling them to and receiving them from a computer does not make it seem that way though.