In the case of Anderson et al. v. United States in 1973, a group of defendants were convicted for conspiring to obstruct interstate commerce by robbery and receiving stolen goods that had crossed state lines. The Supreme Court was asked to determine whether evidence obtained from an illegal wiretap could be used against them, as well as if the government's failure to disclose information about a key witness violated their rights. The court upheld the convictions, ruling that while some evidence may have been improperly admitted due to its origin from an unlawful wiretap, it did not contribute significantly enough towards their conviction and thus constituted "harmless error". Furthermore, they found no violation regarding non-disclosure of information about a key witness since there was no proof this would have affected the trial outcome.

In the dissenting opinion for Anderson et al. v. United States, Justice Douglas argued that the majority's decision to uphold convictions based on evidence obtained through wiretaps violated Fourth Amendment protections against unreasonable searches and seizures. He contended that allowing such evidence was a dangerous precedent, as it could lead to widespread surveillance without proper checks and balances in place. Furthermore, he disagreed with the majority's interpretation of Title III of the Omnibus Crime Control Act - which permits wiretapping under certain circumstances - stating that this law should not be used to justify violations of constitutional rights. In his view, any incriminating information gathered from these wiretaps should have been excluded from trial due to its unconstitutional acquisition.