“Could social media replace search as a way of discovering news? At least for me, to a startling extent it already has. Like many others, I’ve been surprised to realize that I now get an enormous amount of my news via Twitter and Facebook, and now reflexively turn to Twitter — not Google News — as my first stop when news breaks. A year ago, I would have scoffed at that, to say nothing of the idea that I could craft a satisfactory news feed out of links passed along by my peers. But even a cursory look at my own habits shows me that both these things have come to pass.”