In the 1916 case E.I. Du Pont De Nemours Powder Company et al. v. Masland et al., the United States Supreme Court ruled on a dispute involving patent rights and trade secrets in business transactions between two companies, one of which was E.I du Pont de Nemours Powder Company (DuPont). The court held that an employee who leaves a company is not allowed to use or disclose any confidential information obtained during their employment, even if it does not involve patented inventions or processes. This decision established that such knowledge constitutes "trade secrets" protected by law from unauthorized disclosure or use by former employees for their own benefit or for the advantage of competitors. It also affirmed that businesses have a legitimate interest in protecting this type of proprietary information and can seek legal remedies when these interests are violated.

In the dissenting opinion for E.I. DU PONT DE NEMOURS POWDER COMPANY et al. v. MASLAND et al., Justice Holmes disagreed with the majority's ruling that a corporation could be considered a citizen of its state of incorporation, and thus eligible to bring suit in federal court under diversity jurisdiction rules. He argued that corporations are artificial entities created by law and should not enjoy the same rights as natural persons, including citizenship status. Furthermore, he contended that this interpretation was inconsistent with previous rulings on corporate personhood and would lead to an unjust expansion of federal jurisdiction over matters more appropriately handled at the state level.