Is Caller ID phone service legal under Maryland's wiretap and privacy laws?

Plain-English summary

In 1989, the Chesapeake and Potomac Telephone Company filed a tariff with Maryland's Public Service Commission to offer Caller ID, letting a customer see the phone number of an incoming call before answering. The Commission accepted the tariff, but as it opened a broader policy review of Caller ID, the Commission's chairman asked the Attorney General to confirm whether the service was constitutional and consistent with Maryland's wiretap-related statutes.

The AG concluded Caller ID is lawful on both fronts. On the constitutional question, the opinion adopted an earlier letter of advice concluding that a state commission's mere acceptance of a private company's tariff is not "state action" that can trigger due process or Fourth Amendment scrutiny, and that even if it were, courts have held there is no constitutionally protected privacy interest in a telephone number itself, as opposed to the contents of a call, because callers already know the phone company records numbers for billing and other legitimate purposes. On the statutory question, the opinion found that Caller ID technically fits Maryland's definition of a "trap and trace device," which normally requires a court order to use, but that the statute's consent exception applies because the relevant "user" whose consent counts is the person receiving the call, not the caller. Reading "user" to include every possible caller would make the consent exception impossible to satisfy in practice, since callers have no way to consent to something they don't know is happening on the other end of the line.

Common questions

Does approving Caller ID through a state utility commission count as "government action" for privacy purposes?
No, according to the opinion. It concluded that a state commission's mere acceptance of a private telephone company's tariff, without ordering the practice, is not state action sufficient to trigger due process or Fourth Amendment protections.

Is there a constitutional right to keep your phone number private from someone you call?
The opinion said no, drawing on Smith v. Maryland's holding that there is no reasonable expectation of privacy in numbers dialed, because telephone users know the phone company records that information for billing and other business purposes. The opinion applied the same reasoning to the number a call originates from.

Does Maryland law require a court order before Caller ID can capture a caller's number?
Normally, yes, trap-and-trace devices require court authorization. But the opinion concluded Caller ID falls within the statute's consent exception, because the "user" whose consent the law requires is the person receiving calls (the Caller ID subscriber), who consents by signing up for the service, not the calling party.

Why not read "user" to mean the caller, who arguably has more at stake?
The opinion reasoned that reading "user" that broadly would make the consent exception meaningless in practice, since a caller has no way to know a trap and trace device is on the other end of the line and no opportunity to give or withhold consent before the number is captured.

Did any other state reach a different conclusion about Caller ID?
Yes. Pennsylvania's Commonwealth Court, in Barasch v. Pennsylvania Public Utility Comm'n, found Caller ID violated an independent privacy right under the Pennsylvania Constitution and gave a brief, unpersuasive (in the AG's view) treatment of the "user" consent question under Pennsylvania's near-identical trap-and-trace law. The opinion noted Maryland's own Court of Appeals has not identified a similar state constitutional privacy right.

Background and statutory framework

Congress regulated trap and trace devices, distinct from full wiretaps, in the Electronic Communications Privacy Act of 1986, defining a "trap and trace device" as one that captures the incoming signals identifying the originating number of a call (18 U.S.C. §3127(4)). Maryland enacted closely parallel legislation two years later (Chapter 607, Senate Bill 679, Laws of Maryland 1988), codified at Courts Article §10-4B-01 et seq., which the Court of Special Appeals has described as "virtually verbatim" with its federal counterpart (Chan v. State).

Both the federal and Maryland statutes generally require a court order before a trap and trace device may be used, but both exempt use with the consent of "the user of that service" (18 U.S.C. §3121(a); CJ §10-4B-02(a)-(b)). The opinion worked through why "user" in this context means the call recipient rather than the caller: a separate, narrower definition of "user" in the wiretap subtitle (CJ §10-401(12)) does not carry over to the trap-and-trace subtitle, and reading "user" to include callers would make the consent exception a dead letter, since callers cannot consent to a capture they don't know is happening. The opinion also noted that Maryland departs from the federal model by requiring all-party consent for actual wiretaps (CJ §10-402(c)(3), compared to the federal one-party consent rule at 18 U.S.C. §2511(2)(d)), but found no similar departure in the trap-and-trace consent language, reinforcing the reading that a single party's consent, the recipient's, suffices.

The constitutional analysis, adopted from an earlier attached letter of advice, rested on two independent grounds: first, that a state commission's passive acceptance of a private tariff is not state action under Jackson v. Metropolitan Edison Co., so ordinary constitutional restraints on government do not apply to the Commission's approval of Caller ID; and second, that even if state action existed, Smith v. Maryland forecloses any reasonable expectation of privacy in a telephone number itself, as distinct from the content of a call protected under Katz v. United States.

Citations and references

Statutes:

• §10-4B-01, §10-4B-02 of the Courts Article (Maryland's trap and trace device law)
• §10-401(12), §10-402(c)(3) of the Courts Article (wiretap consent standards, for comparison)
• 18 U.S.C. §§2511(2)(d), 3121, 3127 (federal wiretap and trap-and-trace provisions)

Cases:

• Smith v. Maryland, 442 U.S. 735 (1979) (no reasonable expectation of privacy in numbers dialed from a phone)
• Katz v. United States, 389 U.S. 347 (1967) (Fourth Amendment protects the content of telephone conversations)
• Jackson v. Metropolitan Edison Co., 419 U.S. 345 (1974) (a state's mere approval of a private tariff is not state action)
• Chan v. State, 78 Md. App. 287 (1989) (Maryland's trap-and-trace statute mirrors its federal counterpart)
• Barasch v. Pennsylvania Public Utility Comm'n, 576 A.2d 79 (Pa. Cmwlth. 1990) (contrary Pennsylvania decision, distinguished)

Source

• Landing page: https://oag.maryland.gov/resources-info/Pages/attorney-general%E2%80%99s-opinions.aspx
• Original PDF: https://oag.maryland.gov/resources-info/Documents/pdfs/Opinions/1990/Volume75_1990.pdf (this opinion appears at printed pages 382-391 of the bound annual volume; Maryland's site does not publish a standalone PDF of this opinion)

Original opinion text

Best-effort transcription from a scanned PDF. Minor errors may remain, the linked PDF is authoritative.

PUBLIC UTILITIES

Constitutional Law -- Wiretapping -- Caller ID Service is Neither Unconstitutional Nor Contrary to Statute

October 26, 1990

Mr. Frank O. Heintz
Chairman, Public Service Commission

You have requested our opinion concerning the legality of Caller ID telephone service, which enables a customer to see the telephone number from which an incoming call is originating. Specifically, you ask whether Caller ID violates the constitutionally protected right of privacy or statutory provisions governing "trap and trace devices."

For the reasons stated below, we conclude that the Commission's approval of the Caller ID service is neither unconstitutional nor contrary to statute. As your letter points out, Caller ID raises significant policy issues, which the Commission will be exploring and about which this office expresses no views. However, Caller ID may lawfully be offered to Maryland customers.

I

Caller ID Service

On August 31, 1989, the Chesapeake and Potomac Telephone Company of Maryland ("C&P") filed with the Public Service Commission a tariff for several new services, including Caller ID. On September 27, 1989, the Commission accepted C&P's tariff for filing. Thus, C&P was permitted to offer Caller ID to its customers. However, the Commission has now instituted a "in-depth review of the issues surrounding Caller ID ...." Order No. 68858, Case No. 8283 (filed July 9, 1990).

As we understand the facts, whenever a person places a call within C&P's telephone network, C&P's equipment identifies the number from which the call has been placed. This information is often essential for billing purposes.

The new Caller ID service takes this information and makes it available to the potential recipient of a call. As the Commission's order describes it:

    Caller ID enables the customer to see the telephone number from which an incoming call is originating. The number is shown on a display screen which the customer purchases from vendors of telephone equipment. The special telephone unit receives electronic signaling from the telephone company's switching equipment and displays the telephone number of the incoming call. This display allows the called customer to know who is calling before the customer answers the call. Customers who subscribe to Caller ID pay a monthly charge of $6.50 per residential line and a $8.50 per business line.

Order No. 68858, at 1-2.

Thousands of C&P customers have subscribed to Caller ID. The service enables them to identify the source of harassing calls, avoid certain calls, and prepare for other calls by gaining knowledge of the identity of the caller. At the same time, some have objected to the loss of privacy that occurs when a person's telephone number, particularly an unlisted number, is displayed to the person being called. See Order 68858, at 3-4.

II

Constitutional Issues

In an earlier letter of advice, Assistant Attorney General Richard E. Israel concluded that:

1. The Commission's "mere approval of a tariff for a caller identification service does not constitute state action for purposes of the due process clause and the Fourth Amendment"; and

2. Even if there were state action, the display of a telephone number alone does not violate the constitutionally protected right of privacy. Letter to Senator Catherine I. Riley (March 6, 1990).

For the reasons stated in Mr. Israel's letter, a copy of which is attached, we agree with this conclusion. See generally Chan v. State, 78 Md. App. 287, 298-301, 552 A.2d 1351 (1989).[1]

III

Statutory Issues

A. Regulation of "Trap and Trace Devices"

In the Electronic Communications Privacy Act of 1986, Congress regulated the use of pen registers and trap and trace devices, which record telephone numbers rather than the content of telephone conversations. A "trap and trace device" is "a device which captures the incoming electronic or other impulses which identify the originating number of an instrument or device from which a wire or electronic communication was transmitted." 18 U.S.C. §3127(4).[2]

This federal legislation broke new ground, for pen registers and trap and trace devices were not regulated by the federal wiretap law, Title III of the Omnibus Crime Control and Safe Streets Act of 1968. See United States v. New York Telephone Company, 434 U.S. 159, 166 (1977); Chan v. State, 78 Md. App. at 302-03.

Two years later, the General Assembly enacted parallel legislation. Chapter 607 (Senate Bill 679), Laws of Maryland 1988. As the Court of Special Appeals has written, the Maryland statute's "provisions and its wording are virtually verbatim with those of its Federal counterpart." Chan v. State, 78 Md. App. at 308. See Senate Judicial Proceedings Committee, Bill Analysis of Senate Bill 679.[3]

Under the Maryland law, like its federal counterpart, a "trap and trace device" is "a device that captures incoming electronic or other impulses that identify the originating number of an instrument or device from which a wire or electronic communication was transmitted." §10-4B-01(e) of the Courts Article ("CJ" Article). In our view, the Caller ID mechanism is such a "trap and trace device." We recognize that the display screen attached to the telephone of the subscriber to Caller ID does not itself "captur[e] the incoming or other electronic impulses that identify the originating number", instead, C&P's switching equipment does that. Nevertheless, the Caller ID mechanism, taken as a whole, precisely fits the definition, and there is no reason to think that the General Assembly meant to exclude from the statute such a mechanism.

B. Consent Exception

Both the federal law and its Maryland counterpart generally require that a court order be obtained before a trap and trace device may be used. 18 U.S.C. §3121(a); CJ §10-4B-02(a). Just as this restriction is identical in federal and State law, so are the exceptions to it:

    [The requirement for court approval] does not apply to the use of ... a trap and trace device by a provider of wire or electronic communication service:

    (1) Relating to the operation, maintenance, testing of a wire or electronic service or to the protection of the rights or the property of the provider, or to the protection of users of that service from abuse of service or unlawful use of service; or

    (2) To record the fact that a wire or electronic communication was initiated or completed in order to protect the provider, another provider furnishing service toward the completion of the wire communication, or a user of that service, from fraudulent, unlawful, or abusive use of service, or with the consent of the user of that service.

CJ §10-4B-02(b) (emphasis added). The federal provision is essentially identical.[4]

The only exception potentially applicable to Caller ID generally is user consent.[5] The term "user of that service" is not defined for purposes of CJ Title 10, Subtitle 4B, in which the restrictions on trap and trace devices are set out. Nor does the federal statute define "user" in this context.[6]

In ordinary parlance, a caller is as much a "user" of telephone service as the recipient of the call. Indeed, in CJ §10-401(12), the General Assembly defined "user" to mean "any person or entity that... [u]ses an electronic communications service" and is authorized to do so. But this definition is limited to CJ Title 10, Subtitle 4, concerning wiretapping and electronic surveillance, the provisions of which do not apply to trap and trace devices. In our view, the term "user" in Subtitle 4B should not be construed so expansively.

If "user of that service" were understood to include all potential callers, the consent provision for trap and trace devices would become meaningless. A potential caller does not know whether a trap and trace device has been installed on the other end of the line, and the caller's consent cannot be requested prior to the "captur[e]" of the caller's number.[7]

If, however, "user of that service" were understood to refer simply to the recipient of calls in this context, the consent provision in CJ §10-4B-02(b)(2) would not only be practicable but would also be harmonized with its federal counterpart. The latter unquestionably permits installation of a trap and trace device with the consent of the recipient of calls only. Under federal law, an actual wiretap is permissible with the consent of but a single party to the conversation. 18 U.S.C. §2511(2)(d). It is inconceivable that Congress, without discussion, meant to impose a more stringent two-party consent requirement for devices far less intrusive than a wiretap.[8]

To be sure, Maryland has departed from the federal model and requires two-party consent for wiretaps. But the General Assembly's policy choice in this regard is reflected in statutory language different from that of the otherwise parallel federal law. Compare CJ §10-402(c)(3) (wiretap permissible "where all of the parties to the communication have given prior consent") with 18 U.S.C. §2511(2)(d) (wiretap permissible "when one of the parties to the communication has given prior consent"). By contrast, Maryland's consent provision for trap and trace devices does not depart from the federal model.

We recognize that the one court to have addressed the legality of Caller ID, the Commonwealth Court of Pennsylvania, reached the opposite conclusion about the applicability of Pennsylvania's identically worded trap and trace device law. In Barasch v. Pennsylvania Public Utility Comm'n, 576 A.2d 79 (1990), Bell Telephone of Pennsylvania argued in part "that a Caller ID subscriber is the user of the service and consents to use of a trap and trace device by subscribing to Caller ID." 576 A.2d at 85. The court's discussion of this point, in full, is as follows:

    This argument must fail when one considers that "user" includes "any person or entity" who uses the telephone network and that a contrary and reasonable interpretation of that term could also be construed as the calling party rather than the Caller ID subscriber. 18 Pa. C.S. §5702. Hence, Bell's consent analysis fails to support an exception to the Wiretap Act.

Id. In our view, this brief discussion, devoid of analysis, is singularly unpersuasive.

IV

Conclusion

In summary, it is our opinion that the offering of Caller ID service is neither unconstitutional nor otherwise unlawful.

                                          J. Joseph Curran, Jr.
                                          Attorney General

                                          Jack Schwartz
                                          Chief Counsel
                                            Opinions and Advice

Attachment

March 6, 1990

The Honorable Catherine I. Riley
Maryland State Senate

This is in response to your request for advice of counsel on whether the use of a caller identification device on a telephone violates the constitutionally protected right of privacy. As a general rule, constitutional guarantees, such as the right of privacy, are a restraint only on governmental action. Although the Public Service Commission has accepted a telephone company tariff for a caller identification service, ordinarily such limited government action is insufficient to implicate this guarantee. Moreover, it is generally understood that the constitutionally recognized right of privacy protects only the contents of telephone conversations rather than the numbers used in making the calls.

On September 27, 1989, the Public Service Commission accepted a proposed tariff of the Chesapeake and Potomac Telephone Co. to offer a caller identification service. See Minutes of Administrative Meeting of Public Service Commission for Wednesday, September 27, 1989. Where a telephone subscriber wishes to have this service, a device is attached to the telephone which displays the telephone number of incoming calls. The question has arisen whether the use of this device violates the constitutionally protected right of privacy of the person calling.

Although a person's general right of privacy is left largely to State law, various provisions of the Federal Constitution protect individual privacy against certain kinds of governmental intrusion. Katz v. United States, 389 U.S. 347, 350-51 (1967). One of these provisions is the Fourth Amendment which provides as follows:

    The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

This provision is applied to the states through the Due Process Clause of the Fourteenth Amendment. There is a similar provision in the State Constitution. Maryland Declaration of Rights, Article 26.

Although the Fourth Amendment is usually invoked in criminal trials, its protection pertains to all citizens not just criminal suspects. Kimmelman v. Morrison, 477 U.S. 365, 374 (1986). Moreover, it protects the privacy of persons, rather than places. Katz, 389 U.S. at 351. Within the meaning of this Amendment, a "'search' occurs when an expectation of privacy that society is prepared to consider reasonable is infringed." United States v. Jacobsen, 466 U.S. 109, 113 (1984). However, the Fourth Amendment is only a restraint on government. Thus, it does not apply to private parties unless they are acting as agents of the government or acting with the participation or knowledge of government officials. Ibid.

The mere fact that a state regulates a business does not constitute state action for purpose of the Due Process Clause. Jackson v. Metropolitan Edison Co., 419 U.S. 345, 350 (1974). Thus, when a state utility commission approves, but does not order, a practice proposed by a private utility, this approval does not transform this private initiative into state action. Jackson, 419 U.S. at 357. This case was cited by the Circuit Court for Baltimore in the recent case of Sapphire Communications of Maryland, Inc. v. Maryland Public Service Commission, Circuit Court for Baltimore City, Case No. 8833036/CE89917. That case concerned a proposed telephone company tariff for a special "adult call exchange" which would be blocked unless a customer requested the service. The acceptance of the tariff did not, the Court said, constitute state action in a First Amendment challenge. As the Commission is exercising the same authority under Article 78, §27, it follows that mere approval of a tariff for a caller identification service does not constitute state action for purposes of the Due Process Clause and the Fourth Amendment. Of course, the use of caller identification by a government agency might itself be state action. However, there would have to be a protected privacy interest in the number from which the call is made.

In the Katz case, 389 U.S. at 353, it was held that parties to a telephone conversation have a reasonable expectation of privacy which is protected by the Fourth Amendment. However, a distinction has been drawn between the contents of a conversation and the numbers used to make a telephone call. In Smith v. Maryland, 442 U.S. 735, 742-46 (1979), it was held that the use of a pen register, which recorded numbers called from a particular telephone, did not violate the Fourth Amendment as there was no reasonable expectation that the numbers dialed would remain secret. It was noted that "Telephone users ... typically know that they must convey numerical information to the phone company; that the phone company has facilities for recording this information; and that the phone company does in fact record this information for a variety of legitimate business purposes." Smith, 442 U.S. at 743. Of course, the emphasis in the Smith case was on a caller's expectation with respect to the number called, not the number from which the call was made. Id. at 742. Moreover, a subscriber may have obtained an unlisted number with the intent of keeping the number confidential. However, the purpose of a pen register is to record information about the use of a caller's number. Moreover, the Court rejected the contention that there was a special privacy interest in the use of a person's own telephone. Id. at 743. Where a person voluntarily reveals confidential information to a third party, such as a bank or telephone company, there can be no reasonable expectation of privacy. Id. at 743-44. As even an unlisted telephone number is used and recorded by telephone company personnel, this suggests that such a number is not a constitutionally protected privacy interest.

In conclusion, it is my view that the use of caller identification service does not violate the constitutionally protected right of privacy. However, as suggested in the Katz case, the State has broad power to enact legislation to protect privacy interests.

                                          Richard E. Israel
                                          Assistant Attorney General

[1] Barasch v. Pennsylvania Public Utility Comm'n, 576 A.2d 79 (Pa. Cmwlth. 1990), held that Caller ID violated "an independent constitutional right of privacy ... in the Pennsylvania Constitution ...." 576 A.2d at 87. However, "the [Maryland] Court of Appeals has not yet identified any right to privacy protected by the Maryland Constitution." 74 Opinions of the Attorney General 19, 30 (1989).

[2] A "pen register," not directly relevant to this opinion, is "a device which records or decodes electronic or other impulses which identify the numbers dialed or otherwise transmitted on the telephone line to which the device is attached." 18 U.S.C. §3127(3).

[3] The bill was based on a model act prepared by the United States Department of Justice. The portion of the bill dealing with trap and trace devices was not amended.

[4] In the federal statute, the consent language is separately numbered and is phrased, "where the consent of the user of the service has been obtained." 18 U.S.C. §3121(b)(3).

[5] If someone were receiving harassing or obscene calls and ordered Caller ID as a protective measure, the exception "to protect... a user of that service, from ... unlawful or abusive use of service" would apply. That exception, however, would not apply to Caller ID customers who simply want to screen incoming calls for other reasons.

[6] The legislative history of the federal act does not elaborate on the meaning of the term "user." See S. Rep. No. 99-541, 99th Cong., 1st Sess. at 14, reprinted in 1986 U.S. Code Cong. and Admin. News 3555, 3568.

[7] C&P is capable of adding a so-called "blocking" feature to telephone lines, so that a caller can prevent the display of his or her number on a Caller ID display screen. C&P now makes this service available "to certified agencies and individuals who have a unique need to protect their identity or from the location from which they are calling, when initiating telephone calls in the performance of their jobs." Order No. 68858, at 3. Someone who has the blocking feature but does not activate it arguably "consents" to the capture of his or her phone number by the recipient of the call. Even if this blocking feature were universal, however, it would not solve the problem resulting from a construction of the term "user of that service" as embracing all callers. The feature would not be available to callers from pay telephones or telephones not linked to C&P's network. In short, there is no way to achieve consent from the entire universe of potential callers.

[8] See note 6 above.