Here is a link to a wonderful TED talk: 

    “The line between public and private has blurred in the past decade, both online and in real life, and Alessandro Acquisti is here to explain what this means and why it matters. In this http://affectivebrain.com/?attachment_id=5775 thought-provoking, slightly chilling talk, he shares details of recent and ongoing research — including a project that shows how easy it is to match a photograph of a stranger with their sensitive personal information.”