Throughout most of history, humans lived in a state of extreme information poverty. News traveled slowly, field to field, village to village. Even with the printing press’s advent, information spread at a snail’s pace. Few knew how to find printed materials, assuming that they even knew how to read. Today, by contrast, we live in a world of unprecedented media abundance that once would have been the stuff of science-fiction novels. We can increasingly obtain and consume whatever media we want, wherever and whenever we want: television, radio, newspapers, magazines, and the bewildering variety of material available on the Internet....