In the United States v. Mason case of 1910, the Supreme Court ruled on a matter involving fraudulent land entries in Alaska. The defendant, Mason, was charged with making false statements to secure approval for his land claims under an act passed by Congress in 1898 that allowed individuals to claim up to 160 acres of non-mineral public lands in Alaska. He argued that he had not committed fraud because he believed the lands were non-mineral at the time of filing and thus did not knowingly make false declarations. However, it was found that Mason knew about coal deposits on these lands but deliberately concealed this information from authorities when applying for entry rights. The court held that even though there might have been some ambiguity regarding what constituted "mineral" or "non-mineral" lands as per law during those times; such ambiguities could not be used as a defense against charges of deliberate misrepresentation or concealment of facts known at the time of application. Therefore, despite his argument claiming ignorance due to ambiguous laws defining mineral and non-mineral lands during those times; Mason's conviction was upheld by the Supreme Court which concluded him guilty based on evidence proving intentional deception.

In the dissenting opinion for United States v. Mason, 1910, it was argued that the majority's interpretation of the law was too broad and could potentially lead to abuse. The dissenting justices believed that while Congress had indeed granted certain powers to regulatory bodies such as the Interstate Commerce Commission (ICC), these powers were not unlimited. They contended that in this case, where a railroad company had been fined by ICC for giving preferential rates to one customer over another, there should have been more substantial evidence of intent or knowledge on part of the railroad company about its violation before imposing penalties. Furthermore, they expressed concern over potential misuse of power by regulatory agencies if left unchecked and emphasized on maintaining balance between public interest and private rights.