In the case of Schwartz v. Texas, 1952, the U.S. Supreme Court ruled that states are not required to exclude evidence obtained through wiretapping from state trials even if such evidence would be inadmissible in a federal trial due to Fourth Amendment protections against unreasonable searches and seizures. The case arose when an illegal gambling operation was discovered by police using a tapped telephone line without obtaining a warrant first. The defendant argued this violated his constitutional rights under the Fourth Amendment and Fourteenth Amendments but the court disagreed, stating that while it had previously held that wiretap evidence could not be used in federal courts (due to violation of privacy), there was no requirement for states to follow suit unless they chose to do so themselves.

In the dissenting opinion for Schwartz v. Texas, Justice William O. Douglas argued that the majority's decision to uphold a state court ruling allowing wiretap evidence was inconsistent with previous Supreme Court decisions regarding Fourth Amendment protections against unreasonable searches and seizures. He contended that these protections should extend to telephone conversations, as they are private communications not meant for public consumption or use in criminal proceedings without proper authorization or warrants. Furthermore, he expressed concern over potential abuses of power if law enforcement agencies were allowed unrestricted access to such personal information without judicial oversight or due process safeguards in place. This could lead to violations of individuals' privacy rights and civil liberties under the Constitution, which would undermine democratic principles and values at its core.