In the United States v. Ferger et al., 1918, the Supreme Court ruled on a case involving mail fraud. The defendants were accused of using the U.S Postal Service to defraud customers by selling them counterfeit whiskey under false pretenses. They argued that they had not committed mail fraud because their scheme did not involve any falsification of documents sent through the mail; instead, they simply used it as a means to deliver their fraudulent goods. However, Justice Oliver Wendell Holmes Jr., writing for a unanimous court, rejected this argument and held that using the mails for any part of a scheme to defraud constitutes mail fraud under federal law - even if no specific false representations are made in materials mailed or shipped via postal service.

In the dissenting opinion for United States v. Ferger et al., Justice Holmes argued that the majority's interpretation of the law was too broad and could potentially criminalize innocent actions. He believed that a person should only be found guilty if they knowingly and intentionally committed fraud, not simply because they made a mistake or were negligent in their duties. Furthermore, he disagreed with the majority's view that any false statement could constitute fraud, arguing instead that it must be materially false - i.e., significant enough to influence someone's decision-making process - to qualify as such. This narrower interpretation would protect individuals from being unfairly prosecuted for minor errors or misunderstandings while still holding those who deliberately deceive others accountable for their actions.