In the 1943 case Mercoid Corporation v. Mid-Continent Investment Co., the U.S. Supreme Court ruled that a patent holder cannot extend their monopoly beyond the physical item they have patented by creating restrictions on how it can be used or what it can be used with, even if those uses are necessary for its operation. The court held that such practices constitute an unlawful extension of patent rights and violate antitrust laws. This decision was based on two patents owned by Mid-Continent related to heating systems; one for a burner and another for a thermostat control system designed to work with this specific burner type. They sued Mercoid Corp, who were selling devices compatible with these burners but not licensed by Mid-Continent, alleging infringement of both patents.

In the dissenting opinion for MERCOID CORPORATION v. MID-CONTINENT INVESTMENT CO., Justice Robert H. Jackson argued that the majority's decision to invalidate Mercoid's patent claims based on a doctrine of contributory infringement was misguided and could potentially harm future innovation. He contended that this ruling would discourage inventors from seeking patents, as it would allow others to profit off their inventions without any legal repercussions simply by making minor modifications or additions to the original invention. Furthermore, he expressed concern about how this interpretation of patent law might affect competition in various industries, suggesting it could lead to monopolies if companies were able to freely use patented technologies without fear of litigation.