Picture an antitrust action against an apple farmer who supplies almost all the apples in America. If you were bringing the suit for antitrust violation, how would you define the market for an apple? Is it the market for a snack? For healthy snacks? For healthy handheld snacks? For fruits? The list could go on and on. Defining the market for an antitrust analysis becomes far more complicated for products or services that are newer, such as the market for social media networks. When it comes to the Sherman Act one may think that because it has been combatting monopolies for over a century, there can be no room for interpretation about what constitutes a monopoly, much less a market for one. In the past 100 years, however, new markets and questions about those markets have risen. Social media networks probably did not come across the minds of the Sherman Act’s drafters in 1890.

Section 2 of the Sherman Act explains that “Every person who shall monopolize, or attempt to monopolize, or combine or conspire with any other person or persons, to monopolize any part of the trade or commerce among the several states, or with foreign nations, shall be deemed guilty of a felony.” The U.S. Supreme Court has defined two elements of a monopoly under Section 2: “the possession of monopoly power in the relevant market and the willful acquisition or maintenance of that power as distinguished from growth or development as a consequence of a superior product, business acumen, or historic accident.” See United States v. Grinnell, 384 U.S. 563, 570–71 (1966). Monopoly power is defined as the ability to control prices and exclude competition in a given market.