Hanover Shoe, Inc. v. United Shoe Machinery Corp., 392 U.S. 481 (1968), involved an antitrust treble-damages action brought under § 4 of the Clayton Act against a manufacturer of shoe machinery by one of its customers, a manufacturer of shoes. Section 4 of the Clayton Act, 38 Stat. 731, 15 U.S.C.§ 15, provides: 'Any person who shall be injured in his business or property by reason of anything forbidden in the antitrust laws may sue therefor in any district court of the United States in the district in which the defendant resides or is found or has an agent, without respect to the amount in controversy, and shall recover threefold the damages by him sustained, and the cost of suit, including a reasonable attorney's fee.' In defense, the shoe machinery manufacturer sought to show that the plaintiff had not been injured in its business as required by § 4 because it had passed on the claimed illegal overcharge to those who bought shoes from it. Under the defendant's theory, the illegal overcharge was absorbed by the plaintiff's customers - indirect purchasers of the defendant's shoe machinery - who were the persons actually injured by the antitrust violation.