In the case of Dick v. United States in 1907, the U.S Supreme Court upheld a conviction for conspiracy to defraud the government by using mail fraud techniques. The defendants were indicted and convicted under an act of Congress that made it illegal to conspire to commit any offense against or defraud the United States in any manner or for any purpose. They appealed their convictions on grounds that they had been tried under an incorrect statute - one dealing with conspiracies involving land claims rather than postal matters. However, Justice Oliver Wendell Holmes Jr., writing for a unanimous court, rejected this argument stating that while there was indeed separate legislation covering mail fraud specifically, nothing precluded prosecution under more general anti-conspiracy laws if those elements were present in a given case as well.

In the dissenting opinion for Dick v. United States, Justice Harlan argued that the majority's decision to uphold a conviction based on evidence obtained through an illegal search and seizure was fundamentally flawed. He contended that this ruling violated the Fourth Amendment rights of citizens against unreasonable searches and seizures. Harlan believed that allowing such evidence would incentivize law enforcement officers to disregard constitutional protections in their pursuit of criminal convictions, thereby undermining civil liberties. Furthermore, he noted that it is not within the purview of courts to decide whether or not illegally obtained evidence should be admissible; rather, this determination should be left up to legislative bodies who can weigh societal interests against individual rights more effectively than judges can.