Twitter's Moral Flaws, with Mark Hansen

Columbia Journalism School's Mark Hansen, along with his students and "New York Times" journalists, conducted deep, firsthand research into Twitter, buying followers and charting networks, but he was left with even more questions. What does "trending" really mean? How does someone become an influencer, and how is influence wielded? Plus, Hansen describes his innovative art installations, one of which is currently on display at the "New York Times" building in Manhattan.