An information system that relies on advertising was not born with the Internet. But social media platforms have taken it to an entirely new level, becoming a major force in how we make sense of ourselves and the world around us. Columbia law professor Tim Wu, author of The Attention Merchants and The Curse of Bigness, takes us through the birth of the eyeball-centric news model and ensuing boom of yellow journalism, to the backlash that rallied journalists and citizens around creating industry ethics and standards. Throughout the 20th century, radio, television, and even posters elicited excitement, hope, fear, skepticism and greed, and people worked together to create a patchwork of regulation and behavior that attempted to point those tools in the direction of good. The Internet has brought us to just such a crossroads again, but this time with global consequences that are truly life-and-death.