In the 1923 case of Delaney v. United States, the Supreme Court ruled on a matter concerning criminal law and procedure. The defendant, Delaney, was convicted for conspiracy to defraud the U.S government by making false claims against it in violation of Revised Statutes § 5438. He appealed his conviction arguing that he had been denied due process because some evidence used against him was obtained through wiretapping - an act which violated his Fourth Amendment rights protecting him from unreasonable searches and seizures. However, at this time there were no federal laws or constitutional provisions prohibiting wiretapping as a means of gathering evidence so long as it did not involve trespassing private property to install devices (which wasn't done in this case). Therefore, the court upheld Delaney's conviction stating that while they didn't condone such methods of obtaining information; its use did not violate any existing legal principles hence could not be grounds for overturning his sentence.

In the dissenting opinion for Delaney v. United States, Justice McReynolds expressed concern over the majority's decision to uphold a conviction based on evidence obtained through wiretapping. He argued that this practice violated Fourth Amendment protections against unreasonable searches and seizures, as well as Fifth Amendment rights against self-incrimination. The justice contended that allowing such methods of obtaining evidence would set a dangerous precedent, potentially leading to widespread abuses by law enforcement agencies in their efforts to gather information about suspected criminal activities. Furthermore, he believed it was not within the court's purview to decide whether or not these practices were necessary for effective law enforcement; rather, it was their duty to ensure constitutional rights were upheld regardless of potential implications for crime prevention or detection.