In the case of Brown et al. v. United States in 1972, the Supreme Court ruled that a search warrant was not required for law enforcement to seize evidence from an individual's private property if it is within plain view and its incriminating nature is immediately apparent. The case involved two defendants who were convicted on charges of possessing illegal distilling equipment and moonshine whiskey after federal agents conducted a warrantless seizure of their property which was visible from a public road. The defendants argued that this violated their Fourth Amendment rights against unreasonable searches and seizures, but the court disagreed, stating that what can be seen from public places isn't covered by the Fourth Amendment.

In the dissenting opinion for Brown et al. v. United States, Justice Douglas argued that the majority's decision to uphold a conviction based on evidence obtained through warrantless wiretaps was in violation of Fourth Amendment rights against unreasonable searches and seizures. He contended that allowing such evidence would set a dangerous precedent, undermining citizens' privacy rights and potentially leading to widespread governmental abuse of power. Furthermore, he disagreed with the majority's view that national security concerns justified this breach of constitutional protections; instead, he believed these issues should be addressed by Congress rather than being left up to judicial discretion. In his view, any threat posed by domestic organizations did not outweigh individuals' fundamental right to privacy.