concurring.
I agree that the official surveillance of petitioner’s telephone conversations in a public booth must be sub*363jected to the test of reasonableness under the Fourth Amendment and that on the record now before us the particular surveillance undertaken was unreasonable absent a warrant properly authorizing it. This application of the Fourth Amendment need not interfere with legitimate needs of law enforcement.*
In joining the Court’s opinion, I note the Court’s acknowledgment that there are circumstances in which it is reasonable to search without a warrant. In this connection, in footnote 23 the Court points out that today’s decision does not reach national security cases. Wiretapping to protect the security of the Nation has been authorized by successive Presidents. The present Administration would apparently save national security cases from restrictions against wiretapping. See Berger v. New York, 388 U. S. 41, 112-118 (1967) (White, J., *364dissenting). We should not require the warrant procedure and the magistrate’s judgment if the President of the United States or his chief legal officer, the Attorney General, has considered the requirements of national security and authorized electronic surveillance as reasonable.
In previous eases, which are undisturbed by today’s decision, the Court has upheld, as reasonable under the Fourth Amendment, admission at trial of evidence obtained (1) by an undercover police agent to whom a defendant speaks without knowledge that he is in the employ of the police, Hoffa v. United States, 385 U. S. 293 (1966); (2) by a recording device hidden on the person of such an informant, Lopez v. United States, 373 U. S. 427 (1963); Osborn v. United States, 385 U. S. 323 (1966); and (3) by a policeman listening to the secret micro-wave transmissions of an agent conversing with the defendant in another location, On Lee v. United States, 343 U. S. 747 (1952). When one man speaks to another he takes all the risks ordinarily inherent in so doing, including the risk that the man to whom he speaks will make public what he has heard. The Fourth Amendment does not protect against unreliable (or law-abiding) associates, Hofia v. United States, supra. It is but a logical and reasonable extension of this principle that a man take the risk that his hearer, free to memorize what he hears for later verbatim repetitions, is instead recording it or transmitting it to another. The present case deals with an entirely different situation, for as the Court emphasizes the petitioner “sought to exclude . . . the uninvited ear,” and spoke under circumstances in which a reasonable person would assume that uninvited ears were not listening.