May 29, 1979

79-39 MEMORANDUM OPINION FOR THE

DIRECTOR, FEDERAL BUREAU OF

INVESTIGATION

Foreign Intelligence Surveillance Act (50 U.S.C.

§ 1801)—Interception of Radio Communication—

Constitutional Law—Fourth Amendment—Privacy

You have asked this Office to consider whether, in specified circumstances, the Federal Bureau of Investigation (FBI) interception of 

radio transmissions' would constitute “ electronic surveillance” as that 

term is defined by § 101(0 of the Foreign Intelligence Surveillance Act of 

1978 (FISA), Pub. L. No. 95-511, 92 Stat. 1785, 50 U.S.C. § 1801(0- We 

conclude, for reasons discussed below, that the interception of such transmissions is not “ electronic surveillance” and does not require a warrant 

when conducted to gather foreign intelligence information.

I. Statutory Interpretation

As analyzed below, whether the interception of radio transmissions is 

“ electronic surveillance” under FISA turns, in general, on whether the 

speaker has a constitutionally protected reasonable expectation of privacy 

with respect to his communications.

Under FISA, the interception of radio communications could potentially be classed as “ electronic surveillance” under either of two subsections of § 101(0- Section 101(0 provides:

“ Electronic surveillance” means—

(1) the acquisition by an electronic, mechanical, or other 

surveillance device of the contents of any wire or radio

1 References in this memorandum to “ radio communications” include only two-way communications wholly between radio stations or one-way communications between a transmitter and a receiver, and not microwave or other radio communications that rely, in part, on 

wire, cable, or similar transmissions.

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communications sent by or intended to be received by a particular, known United States person who is in the United 

States, if the contents are acquired by intentionally targeting 

that United States person, under circumstances in which a person has a reasonable expectation of privacy and a warrant 

would be required for law enforcement purposes;

*******

(3) the intentional acquisition by an electronic, mechanical, 

or other surveillance device of the contents of any radio communication, under circumstances in which a person has a 

reasonable expectation of privacy and a warrant would be required for law enforcement purposes, and if both the sender 

and all intended recipients are located within the United 

States; * * *.

The interception of the communications involved would typically fall 

within one of these subsections unless the person targeted, or whose communications were intercepted, had no “ reasonable expectation of 

privacy.” Congress meant to incorporate into FISA the standard for constitutionally protected privacy interests that is set forth in Katz v. United

States, 389 U.S. 347 (1967). Katz held that the warrantless electronic 

surveillance of a telephone conversation initiated in a public telephone 

booth was unconstitutional because it “ violated the privacy on which [the 

speaker] justifiably relied.” Id. at 353. The Court found that the speaker 

“justifiably” relied on the privacy of his conversation because of both an 

objectively reasonable social expectation that people’s phone conversations will be private and the speaker’s own efforts to keep the world outside the phone booth from hearing his conversation. Congress did not 

specify in the language of FISA whether it meant to protect only such 

socially accepted, actively sought conditions of privacy or whether it intended to adopt a broader privacy concept. Both the House and the 

Senate, however, in reporting the bills that became FISA, said:

The * * * definitions of “ electronic surveillance” require that 

the acquisition of information be under circumstances in which a 

person has a constitutionally protected right of privacy. [H.

Rept. 1283, Pt. I, 95th Cong., 2d sess. 53 (1978); S. Rept. 701, 

id., at 37 (1978).]

Nothing in the Act or in the legislative history contradicts these statements 

that the privacy standard in FISA is the same as the Fourth Amendment 

standard.

The second factor determining whether an interception of radio communications constitutes “ electronic surveillance” under FISA is whether 

“ a warrant would be required for law enforcement purposes.” Under the 

relevant statute, Title III of the Omnibus Crime Control and Safe Streets 

Act of 1968, 18 U.S.C. § 2510 et seq:, a warrant is required for the

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interception, for law enforcement purposes, of radio communications 

only if the person speaking has a constitutionally protected reasonable expectation of privacy. This conclusion follows from the definitional sections of title III. The communications covered by title III are divided into 

two categories, “ wire” and “ oral.” A “ wire communication” is:

* * * any communication made in whole or in part through the 

use of facilities for the transmission of communications by the 

aid of wire, cable, or other like connection between the point of 

origin and the point of reception furnished or operated by any 

person engaged as a common carrier in providing or operating 

such facilities for the transmission of interstate or foreign communications * * *. [18 U.S.C. §2510(1).]

An “ oral communication” is:

♦ * * any oral communication uttered by a person exhibiting an 

expectation that such communication is not subject to interception under circumstances justifying such expectation * * *. [18 

U.S.C. §2510(2).]

It is evident that, although radio transceivers use wires, a normal radio 

communication does not fall within the defmition of “ wire communications,” which includes only those communications that are transmitted, in 

whole or in part, over the wire or cable facilities of a communications 

common carrier. An ordinary radio communication, on its face, is more 

directly analogous to an oral utterance, whose audible reach is extended 

through the open air mechanically through a device such as a megaphone. 

The Ninth Circuit Court of Appeals has held that radio communications, 

if covered at all by title III, are covered as “ oral communications” as 

defined in that Act. United States v. Hall, 488 F. (2d) 193, 196-197 (9th 

Cir. 1973).

However, as indicated in the definition quoted above, title III requires a 

warrant to intercept oral communications only when uttered by persons 

possessing a justifiable expectation of privacy. 18 U.S.C. § 2510(2). Title 

III, like FISA, thus incorporates the constitutional privacy standard first 

set forth in Katz.1 If, in particular circumstances, no justifiable expectation of privacy requiring a warrant for law enforcement purposes under 

the Fourth Amendment exists, title III imposes no warrant requirement 

for the interception of oral communications.

Because “ electronic surveillance” of radio communications is defined 

under FISA to include only circumstances in which a constitutionally protected privacy interest exists, and because a warrant for law enforcement 

purposes would be required under title III or under the Constitution only 

where there is a constitutionally protected privacy interest, the

1 “ In the course o f the opinion [Berger v. New York, 388 U.S. 41 (1967)], the Court 

delineated the Constitutional criteria that electronic surveillance legislation should contain. 

Title III was drafted to meet these standards and to conform with Katz v. United States, 389 

U.S. 347 (1967).” S. Rept. 1097, 90th Cong., 2d sess., 66 (1968). See also, id. at 28, 89-90.

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existence of such an interest controls both definitional characteristics of 

“ electronic surveillance” under FISA.

n . Expectations of Privacy and Radio Transmissions

Having concluded that the interpretation of “ electronic surveillance” 

under FISA turns, in this instance, on a determination whether persons using radio have a constitutionally protected expectation of privacy, it is 

necessary to ascertain whether any such interest exists.

In Katz, the Supreme Court held that the Fourth Amendment protected 

not particular places, but certain privacy interests of persons:

What a person knowingly exposes to the public, even in his home 

or office, is not a subject of Fourth Amendment protection * * *. But what he seeks to preserve as private, even in an 

area accessible to the public, may be constitutionally protected.

[Id. at 351-2 (citations omitted).]

From this foundational statement, courts have deduced that the reasonableness of an expectation of privacy is to be judged by those factors affecting the person’s subjective expectations, and by “ understandings that 

are recognized and permitted by society” concerning privacy. Rakas v. Illinois, 99 S. Ct. 421, 430-431, n. 12 (1978). As explained below, we conclude from a review of such factors that no constitutionally protected expectation of privacy exists with respect to most radio communications.

First, a person using an ordinary radio is knowingly exposing the 

message transmitted to any member of the public who happens to be 

listening. The ease of interception, the widespread availability of the 

technology required for interception,-and the ease of access for the user to 

more private means of communication all suggest that no subjective 

reliance on a privacy interest occurs in the case of a radio message.

The fact that a specific interception that actually takes place may not 

have been anticipated does not mean there is a constitutionally protected 

privacy interest. Case law clearly demonstrates that once a person exposes 

an otherwise private event to ready observation, the individual cannot 

legitimately rely on an expectation of privacy created by the possibility 

that the public will overlook what has been exposed. See, e.g., United

States v. Jackson, 448 F. (2d) 963, 971 (9th Cir. 1971), cert, denied, 405 

U.S. 924 (1972) (upholding the warrantless search of a trash can outside a 

hotel room); United States v. Fisch, 474 F. (2d) 1071 (9th Cir. 1973), cert, 

denied, 412 U.S. 921 (1973), and United States v. Llanes, 398 F. (2d) 880 

(2d Cir. 1968), cert, denied, 393 U.S. 1032 (1969) (upholding warrantless 

eavesdropping, with the naked ear, of a conversation in an adjoining 

motel room or apartment); and United States v. Wright, 449 F. (2d) 1355 

(D.C. Cir. 1971), cert, denied, 405 U.S. 947 (1972) (upholding warrantless 

visual search of a garage, using a flashlight, through partially open garage 

door).

The circumstances surrounding radio transmissions and analogies from

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existing case law support the conclusion that a person transmitting a 

message by radio cannot reasonably rely on an expectation of privacy in 

the constitutional sense.3 Nor does it appear that there are, with respect to 

radio, any “ understandings recognized and permitted by society,” Rakas

v. Illinois, 99 S. Ct. 421, 430-31, n. 12 (1978), that create a constitutionally protected privacy interest.

It might be argued that § 605 of the Federal Communications Act of 

1934, as amended, 47 U.S.C. § 605, creates a right of privacy that gives 

rise to a constitutionally protected expectation of privacy. Section 605 provides in part:

No person not being authorized by the sender shall intercept any 

radio communication and divulge or publish the existence, contents, substance, purport, effect, or meaning of such intercepted 

communication to any person.

Prior to its amendment in 1968, this provision referred to “ any” communication “ by wire or radio,” and was interpreted by the Supreme Court 

to preclude the introduction into evidence of intercepted wire communications at a State or Federal trial. Nardone v. United States, 302 U.S. 379 

(1937); Lee v. Florida, 392 U.S. 378 (1968). Reasoning from Nardone, the 

Ninth Circuit, in United States v. Sugden, 226 F. (2d) 281 (9th Cir. 1955), 

aff’d per curiam, 351 U.S. 916 (1956), held the exclusionary rule applicable to radio communications as well.

We conclude, however, that the prohibitions enacted in § 605 do not 

codify or create a constitutionally protected privacy interest for radio 

communications. First, those lower courts that ruled on the question prior 

to FISA held that § 605 does not bar warrantless electronic surveillance for 

the purpose of gathering foreign intelligence information, even from wire 

communications. United States v. Butenko, 494 F. (2d) 593, 602 (3d Cir.

1974), cert, denied, 419 U.S. 881 (1974); United States v. Clay, 430 F. (2d) 

165, 171 (5th Cir. 1970), rev’d on other grounds, 403 U.S. 698 (1971); 

United States v. Hoffman, 334 F. Supp. 504 (D.D.C. 1971). In adopting 

FISA, Congress provided expressly that § 605 is not a bar to “ electronic 

surveillance” conducted under the Act, or to the acquisition of foreign 

intelligence information by means other than electronic surveillance from 

international or foreign communications. FISA, § 201(b), 18 U.S.C. 

§ 2511(2)(e) and (f). In view of the prior case law and because Congress

’ The fact that a transmission may be encoded would also not create a constitutionally protected privacy interest. With respect to communications, the Fourth Amendment protects 

persons against interceptions that cannot be reasonably anticipated, given the steps taken to 

protect the privacy o f the communication. In circumstances in which the Fourth Amendment 

would not proscribe a particular recipient from receiving a communication, the recipient’s 

use o f the communication, e.g., decoding, divulgence to a third party, etc., is not a m atter of 

constitutional concern. H offa v. United States, 385 U.S. 293, 300-303 (1966); United States

v. Crowell, 586 F. (2d) 1020 (4th Cir. 1978), cert, denied, 99 S.Ct. 1500 (1979) (permitting 

police to take and subject to chemical analysis defendant’s trash “ absent proof that [defendant] has made some special arrangement for the disposition o f his trash inviolate” ).

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stated expressly that § 605 does not bar domestic “ electronic 

surveillance,” which, by definition, occurs only when a constitutional 

privacy interest is at stake, it should follow that § 605 does not bar the acquisition of foreign intelligence information in cases in which a constitutionally protected privacy interest is not at stake. Assuming that § 605 is 

thus simply irrelevant to the gathering of foreign intelligence information, 

a person transmitting an ordinary radio message cannot justifiably rely on 

§ 605 as protecting his privacy against investigators seeking such 

information.

Second, the Department of Justice has consistently interpreted § 605 not 

to bar the mere acquisition of radio communications, but only to proscribe their interception and divulgence outside the Government, see H. 

Rept. 1283, Pt. 1, 95th Cong., 2d sess. 15 (1978), and a person using radio 

could thus not rely on § 605 as guaranteeing privacy against mere 

interception.4

III. Conclusion

We conclude that no constitutionally protected privacy interest exists 

with respect to ordinary radio transmissions and, consequently, that no 

warrant is required for the interception of most radio communications for 

law enforcement purposes. Because there is thus, with respect to such 

communications, neither a “ reasonable expectation of privacy” nor a 

warrant requirement for law enforcement purposes, the interception of 

radio communications does not constitute “ electronic surveillance” 

within the definitional provisions of FISA.

K e n n e t h C . B a s s , III 

Counsel for Intelligence Policy

Office o f Legal Counsel

4 Our interpretation is consistent with United States v. Hall, 488 F. (2d) 193 (9th Cir. 

1973), in which the court held that no constitutional right of privacy attaches to radio communications in a case in which the speaker recognizes the possibility of interception. The 

court regarded the 1968 revision o f § 60S as exempting law enforcement officers from its 

coverage, and thus found § 605’s ban on divulgence irrelevant to the introduction into 

evidence at trial o f the contents of intercepted radio communications. Judge Ferguson 

dissented on the ground that § 60S did apply to law enforcement officers, and did proscribe 

the use o f intercepted conversations at trial. He took no exception, however, to the 

majority’s assumption that § 605 was irrelevant to the question whether a constitutional right 

o f privacy attaches to radio-to-radio communications.

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