Twitter Watch: Library of Congress keeps tweets on file unavailable to public

In the 7 years since its inception, Twitter has become an integral part of twenty first century life. Reflecting everything, from people's routine habits, to revolutionary political messages. And for the last 2 years, every single tweet sent in the U.S. has been stored in a massive archive at the Library of Congress - raising concerns over privacy. The official reason is for research purposes - but so far the data has been kept behind closed doors.