Amazon, Apple, Facebook, and Google have affected the way that billions of people live their lives—transforming the U.S. economy and society over the last decade. But various state and federal entities have recently opened as many as 16 investigations into the companies. A common question underlies many of these inquiries: Does big tech have too much power—and too little oversight and regulation? “Without the discipline of meaningful market-based competition, digital platforms may act in ways that are not responsive to consumer demands,” said U.S. Assistant Attorney General Makan Delrahim, the head of the Antitrust Division of the U.S. Department of Justice, when the Justice Department announced that it will investigate certain large tech ...