Carnegie Mellon University conducted a study following more than 5,000 Facebook users over six years, from 2005 and 2011, and found that changes in the social network's privacy policies caused users to share more -- not less -- personal data. Lest you think this means that users suddenly trusted the site more, Carnegie Mellon says that Facebookers became more and more protective of their personal details as the social network grew in membership -- and that the uptick in shared information is a result of increasingly granu