The modern antitrust enterprise finds itself under attack. Critics complain that enforcement agencies have done nothing to stem an ever-rising tide of market concentration and corporate power. At the center of this critique lies Silicon Valley, home of a new generation of tech giants. This symposium contribution contends that attention markets represent the largest sector of the modern economy to have gone unnoticed by antitrust regulators. If it is to fulfill its congressional mandate, the antitrust enterprise must begin paying attention to attention markets. A number of objections to this straightforward point have been raised, but each collapses under close scrutiny. This article catalogues and refutes each of those objections, and conc...