In the case of Dann, Commissioner of Patents and Trademarks v. Johnston in 1975, the United States Supreme Court ruled on a patent dispute involving computer technology. The petitioner, C. Marshall Dann as Commissioner of Patents and Trademarks, argued that respondent William R. Johnston's invention was not patentable because it did not meet certain statutory requirements for novelty and non-obviousness under U.S Patent Law (35 U.S.C §103). The invention in question was a system for automatic record keeping of bank checks and deposits using data processing equipment. The court held that while the method may have been new to banking industry practices at the time, it was essentially an obvious application of existing technologies rather than a novel innovation deserving protection under patent law. Therefore, they affirmed with modification the decision by lower courts denying issuance of a patent to Mr.Johnston.

In the dissenting opinion for Dann, Commissioner of Patents and Trademarks v. Johnston, Justice William O. Douglas argued that the majority's decision was too restrictive in its interpretation of what constitutes patentable subject matter under Section 101 of the Patent Act. He contended that this narrow view could stifle innovation and limit future technological advancements by excluding certain types of inventions from being eligible for patent protection. Specifically, he disagreed with the majority's assertion that a mathematical algorithm cannot be patented because it is an abstract idea rather than a process or machine as defined by law. In his view, if such an algorithm produces a useful result when applied to a computer system or other technology, then it should qualify as patentable subject matter.