In the 1968 case Zenith Radio Corp. v. Hazeltine Research, Inc., the U.S Supreme Court ruled in favor of Zenith Radio Corporation (Zenith). The dispute centered around a patent licensing agreement between Hazeltine Research, Inc. (Hazeltine) and its Canadian subsidiary, which required that all patents be licensed as a package rather than individually - an arrangement known as "block-booking". Zenith argued this was illegal under antitrust laws because it forced them to pay for licenses they did not need or want when purchasing those they did require from the Canadian company. The court agreed with Zenith's argument that block-booking violated both U.S and Canadian anti-trust laws by restraining trade and suppressing competition in violation of Sherman Act Section 1 & Clayton Act Section 3 respectively; thus reversing lower courts' decisions which had favored Hazeltine.

In the dissenting opinion for Zenith Radio Corp. v. Hazeltine Research, Inc., Justice Harlan argued that the majority's decision to allow a patent holder to collect damages from an infringer even after the patent has expired contradicts established legal principles and could lead to unjust outcomes. He contended that once a patent expires, it enters into public domain and anyone should be able to use it without fear of being sued for infringement. Therefore, he reasoned, allowing a company like Hazeltine Research Inc., which had already profited immensely from its patents during their term of protection, to continue collecting royalties indefinitely would amount to granting them perpetual monopoly rights over their inventions - something antithetical both in spirit and letter of Patent Law as well as Antitrust Laws designed specifically against such monopolistic practices.