Roy Olmstead and his associates ran a liquor business during the prohibition period. The government built its case against him based upon warrantless wiretaps on his home and business telephones. Olmstead et. al. contended that the use of the wiretaps violated their rights under the Fourth and Fifth Amendments. The Supreme Court ruled 5-4 against them. The decision was later reversed by Katz v. United States in 1967.
History best remembers Olmstead for the dissenting opinion of Justice Louis Brandeis:
The makers of our Constitution ... sought to protect Americans in their beliefs, their thoughts, their emotions and their sensations. They conferred, as against the government, the right to be let alone-the most comprehensive of rights and the right most valued by civilized men. To protect that right, every unjustifiable intrusion by the government upon the privacy of the individual, whatever the means employed, must be deemed a violation of the Fourth Amendment.
It is, of course, immaterial where the physical connection with the telephone wires leading into the defendants' premises was made. And it is also immaterial that the intrusion was in aid of law enforcement. Experience should teach us to be most on our guard to protect liberty when the government's purposes are beneficent. Men born to freedom are naturally alert to repel invasion of their liberty by evil-minded rulers. The greatest dangers to liberty lurk in insidious encroachment by men of zeal, well-meaning but without understanding.
Decency, security, and liberty alike demand that government officials shall be subjected to the same rules of conduct that are commands to the citizen. In a government of laws, existence of the government will be imperiled if it fails to observe the law scrupulously. Our government is the potent, the omnipresent teacher. For good or for ill, it teaches the whole people by its example. Crime is contagious. If the government becomes a lawbreaker, it breeds contempt for law; it invites every man to become a law unto himself; it invites anarchy. To declare that in the administration of the criminal law the end justifies the means-to declare that the government may commit crimes in order to secure the conviction of a private criminal-would bring terrible retribution. Against that pernicious doctrine this court should resolutely set its face.