In the 1973 case DeMarco v. United States, the Supreme Court ruled on a matter involving tax evasion and fraud. The defendant, DeMarco, was convicted of evading federal income taxes by underreporting his income from illegal gambling operations. He appealed to the Supreme Court arguing that evidence used against him had been obtained illegally because it was seized without a warrant during an unrelated investigation into his alleged involvement in interstate transportation of stolen property. The court rejected this argument stating that since he voluntarily gave up possession of these records when they were initially seized for another crime, their use in subsequent investigations did not violate his Fourth Amendment rights against unreasonable searches and seizures.

In the dissenting opinion for DeMarco v. United States, it was argued that the majority's decision to uphold a conviction based on evidence obtained through warrantless wiretapping violated Fourth Amendment protections against unreasonable searches and seizures. The dissent emphasized that such surveillance should only be permitted in exceptional circumstances where obtaining a warrant is not feasible due to immediate danger or risk of evidence destruction. It was also pointed out that allowing this kind of intrusion without proper judicial oversight could lead to potential abuses by law enforcement agencies, undermining citizens' privacy rights and civil liberties. Furthermore, they disagreed with the majority’s view about “consent” given under duress being valid consent for search purposes; arguing instead that true consent cannot be given under threat or coercion as it negates its voluntary nature which is essential for any legal consent.