United States v. Jones

concurring in the judgment.

This case requires us to apply the Fourth Amendment’s prohibition of unreasonable searches and seizures to a 21st-­century surveillance technique, the use of a Global Position­ing System (GPS) device to monitor a vehicle’s movements for an extended period of time. Ironically, the Court has chosen to decide this case based on 18th-century tort law. By attaching a small GPS device1 to the underside of the *419vehicle that respondent drove, the law enforcement officers in this case engaged in conduct that might have provided grounds in 1791 for a suit for trespass to chattels.2 And for this reason, the Court concludes, the installation and use of the GPS device constituted a search. Ante, at 404-405.

This holding, in my judgment, is unwise. It strains the language of the Fourth Amendment; it has little if any support in current Fourth Amendment case law; and it is highly artificial.

I would analyze the question presented in this case by asking whether respondent’s reasonable expectations of pri­vacy were violated by the long-term monitoring of the move­ments of the vehicle he drove.

I — l

A

The Fourth Amendment prohibits “unreasonable searches and seizures,” and the Court makes very little effort to ex­plain how the attachment or use of the GPS device fits within these terms. The Court does not contend that there was a seizure. A seizure of property occurs when there is “some meaningful interference with an individual’s possessory in­terests in that property,” United States v. Jacobsen, 466 U. S. 109, 113 (1984), and here there was none. Indeed, the suc­cess of the surveillance technique that the officers employed was dependent on the fact that the GPS did not interfere in any way with the operation of the vehicle, for if any such interference had been detected, the device might have been discovered.

*420The Court does claim that the installation and use of the GPS constituted a search, see ante, at 404-405, but this con­clusion is dependent on the questionable proposition that these two procedures cannot be separated for purposes of Fourth Amendment analysis. If these two procedures are analyzed separately, it is not at all clear from the Court’s opinion why either should be regarded as a search. It is clear that the attachment of the GPS device was not itself a search; if the device had not functioned or if the officers had not used it, no information would have been obtained. And the Court does not contend that the use of the device consti­tuted a search either. On the contrary, the Court accepts the holding in United States v. Knotts, 460 U. S. 276 (1983), that the use of a surreptitiously planted electronic device to monitor a vehicle’s movements on public roads did not amount to a search. See ante, at 408-409.

The Court argues — and I agree — that “we must ‘assur[e] preservation of that degree of privacy against government that existed when the Fourth Amendment was adopted.’” Ante, at 406 (quoting Kyllo v. United States, 533 U. S. 27, 34 (2001)). But it is almost impossible to think of late-18th­century situations that are analogous to what took place in this case. (Is it possible to imagine a case in which a consta­ble secreted himself somewhere in a coach and remained there for a period of time in order to monitor the movements of the coach’s owner?3) The Court’s theory seems to be that the concept of a search, as originally understood, compre­hended any technical trespass that led to the gathering of evidence, but we know that this is incorrect. At common law, any unauthorized intrusion on private property was ac­tionable, see Prosser & Keeton 75, but a trespass on open fields, as opposed to the “curtilage” of a home, does not fall *421within the scope of the Fourth Amendment because private property outside the curtilage is not part of a “hous[e]” within the meaning of the Fourth Amendment. See Oliver v. United States, 466 U. S. 170 (1984); Hester v. United States, 265 U. S. 57 (1924).

B

The Court’s reasoning in this case is very similar to that in the Court’s early decisions involving wiretapping and elec­tronic eavesdropping, namely, that a technical trespass fol­lowed by the gathering of evidence constitutes a search. In the early electronic surveillance cases, the Court concluded that a Fourth Amendment search occurred when private con­versations were monitored as a result of an “unauthorized physical penetration into the premises occupied” by the de­fendant. Silverman v. United States, 365 U. S. 505, 509 (1961). In Silverman, police officers listened to conversa­tions in an attached home by inserting a “spike mike” through the wall that this house shared with the vacant house next door. Id., at 506. This procedure was held to be a search because the mike made contact with a heating duct on the other side of the wall and thus “usurpfed] ... an integral part of the premises.” Id., at 511.

By contrast, in cases in which there was no trespass, it was held that there was no search. Thus, in Olmstead v. United States, 277 U. S. 438 (1928), the Court found that the Fourth Amendment did not apply because “[t]he taps from house lines were made in the streets near the houses.” Id., at 457. Similarly, the Court concluded that no search oc­curred in Goldman v. United States, 316 U. S. 129,135 (1942), where a “detectaphone” was placed on the outer wall of de­fendant’s office for the purpose of overhearing conversations held within the room.

This trespass-based rule was repeatedly criticized. In Olmstead, Justice Brandéis wrote that it was “immate­rial where the physical connection with the telephone wires . . . was made.” 277 U. S., at 479 (dissenting opinion). Al­*422though a private conversation transmitted by wire did not fall within the literal words of the Fourth Amendment, he argued, the Amendment should be understood as prohibiting “every unjustifiable intrusion by the Government upon the privacy of the individual.” Id., at 478. See also, e. g., Sil-­verman, supra, at 513 (Douglas, J., concurring) (“The con­cept of ‘an unauthorized physical penetration into the prem­ises/ on which the present decision rests, seems to me beside the point. Was not the wrong ... done when the intimacies of the home were tapped, recorded, or revealed? The depth of the penetration of the electronic device — even the degree of its remoteness from the inside of the house — is not the measure of the injury”); Goldman, supra, at 139 (Murphy, J., dissenting) (“[Tjhe search of one’s home or office no longer requires physical entry, for science has brought forth far more effective devices for the invasion of a person’s privacy than the direct and obvious methods of oppression which were detested by our forebears and which inspired the Fourth Amendment”).

Katz v. United States, 389 U. S. 347 (1967), finally did away with the old approach, holding that a trespass was not re­quired for a Fourth Amendment violation. Katz involved the use of a listening device that was attached to the outside of a public telephone booth and that allowed police officers to eavesdrop on one end of the target’s phone conversation. This procedure did not physically intrude on the area occu­pied by the target, but the Katz Court “repudiate[ed]” the old doctrine, Rakas v. Illinois, 439 U. S. 128, 143 (1978), and held that “[t]he fact that the electronic device employed . . . did not happen to penetrate the wall of the booth can have no constitutional significance,” 389 U. S., at 353; ibid. (“[T]he reach of th[e] [Fourth] Amendment cannot turn upon the presence or absence of a physical intrusion into any given enclosure”); see Rakas, supra, at 143 (describing Katz as holding that the “capacity to claim the protection for the Fourth Amendment depends not upon a property right in *423the invaded place but upon whether the person who claims the protection of the Amendment has a legitimate expecta­tion of privacy in the invaded place”); Kyllo, 533 U. S., at 32 (“We have since decoupled violation of a person’s Fourth Amendment rights from trespassory violation of his prop­erty”). What mattered, the Court now held, was whether the conduct at issue “violated the privacy upon which [the defendant] justifiably relied while using the telephone booth.” Katz, supra, at 353.

Under this approach, as the Court later put it when ad­dressing the relevance of a technical trespass, “an actual trespass is neither necessary nor sufficient to establish a constitutional violation.” United States v. Karo, 468 U. S. 705, 713 (1984) (emphasis added). Ibid. (“[e]ompar[ing] Katz v. United States, 389 U. S. 347 (1967) (no trespass, but Fourth Amendment violation), with Oliver v. United States, 466 U. S. 170 (1984) (trespass, but no Fourth Amendment viola­tion)”). In Oliver, the Court wrote:

“The existence of a property right is but one element in determining whether expectations of privacy are legiti­mate. ‘The premise that property interests control the right of the Government to search and seize has been discredited.’ Katz, 389 U. S., at 353 (quoting Warden v. Hayden, 387 U. S. 294, 304 (1967).” 466 U. S., at 183 (some internal quotation marks omitted).

FH FH

The majority suggests that two post-Katz decisions— Soldal v. Cook County, 506 U. S. 56 (1992), and Alderman v. United States, 394 U. S. 165 (1969) — show that a technical trespass is sufficient to establish the existence of a search, but they provide little support.

In Soldal, the Court held that towing away a trailer home without the owner’s consent constituted a seizure even if this did not invade the occupants’ personal privacy. But in the *424present case, the Court does not find that there was a sei­zure, and it is clear that none occurred.

In Alderman, the Court held that the Fourth Amendment rights of homeowners were implicated by the use of a surrep­titiously planted listening device to monitor third-party con­versations that occurred within their home. See 394 U. S., at 176-180. Alderman is best understood to mean that the homeowners had a legitimate expectation of privacy in all conversations that took place under their roof. See Rakas, supra, at 144, n. 12 (citing Alderman for the proposition that “the Court has not altogether abandoned use of property concepts in determining the presence or absence of the pri­vacy interests protected by that Amendment”); 439 U. S., at 153 (Powell, J., concurring) (citing Alderman for the proposi­tion that “property rights reflect society’s explicit recogni­tion of a person’s authority to act as he wishes in certain areas, and therefore should be considered in determining whether an individual’s expectations of privacy are reason­able); Karo, supra, at 732 (Stevens, J., concurring in part and dissenting in part) (citing Alderman in support of the proposition that “a homeowner has a reasonable expectation of privacy in the contents of his home, including items owned by others”).

In sum, the majority is hard pressed to find support in post-Katz cases for its trespass-based theory.

1 — I HH HH

Disharmony with a substantial body of existing ease law is only one of the problems with the Court’s approach in this case.

I will briefly note four others. First, the Court’s reason­ing largely disregards what is really important (the use of a GPS for the purpose of long-term tracking) and instead at­taches great significance to something that most would view as relatively minor (attaching to the bottom of a car a small, light object that does not interfere in any way with the car’s *425operation). Attaching such an object is generally regarded as so trivial that it does not provide a basis for recovery under modern tort law. See Prosser & Keeton § 14, at 87 (harmless or trivial contact with personal property not ac­tionable); D. Dobbs, Law of Torts 124 (2000) (same). But under the Court’s reasoning, this conduct may violate the Fourth Amendment. By contrast, if long-term monitor­ing can be accomplished without committing a technical trespass — suppose, for example, that the Federal Govern­ment required or persuaded auto manufacturers to include a GPS tracking device in every car — the Court’s theory would provide no protection.

Second, the Court’s approach leads to incongruous results. If the police attach a GPS device to a car and use the device to follow the car for even a brief time, under the Court’s theory, the Fourth Amendment applies. But if the police follow the same car for a much longer period using unmarked cars and aerial assistance, this tracking is not subject to any Fourth Amendment constraints.

In the present case, the Fourth Amendment applies, the Court concludes, because the officers installed the GPS de­vice after respondent’s wife, to whom the car was registered, turned it over to respondent for his exclusive use. See ante, at 404-405. But if the GPS had been attached prior to that time, the Court’s theory would lead to a different result. The Court proceeds on the assumption that respondent “had at least the property rights of a bailee,” ante, at 404, n. 2, but a bailee may sue for a trespass to chattel only if the injury occurs during the term of the bailment. See 8A Am. Jur. 2d, Bailment § 166, pp. 685-686 (2009). So if the GPS device had been installed before respondent’s wife gave him the keys, respondent would have no claim for trespass — and, presumably, no Fourth Amendment claim either.

Third, under the Court’s theory, the coverage of the Fourth Amendment may vary from State to State. If the events at issue here had occurred in a community-property *426State4 or a State that has adopted the Uniform Marital Prop­erty Act,5 respondent would likely be an owner of the vehi­cle, and it would not matter whether the GPS was installed before or after his wife turned over the keys. In non-­community-property States, on the other hand, the regis­tration of the vehicle in the name of respondent’s wife would generally be regarded as presumptive evidence that she was the sole owner. See 60 C. J. S., Motor Vehicles § 231, pp. 398-399 (2002); 8 Am. Jur. 2d, Automobiles § 1208, pp. 859-860 (2007).

Fourth, the Court’s reliance on the law of trespass will present particularly vexing problems in cases involving sur­veillance that is carried out by making electronic, as opposed to physical, contact with the item to be tracked. For exam­ple, suppose that the officers in the present case had followed respondent by surreptitiously activating a stolen vehicle de­tection system that came with the car when it was pur­chased. Would the sending of a radio signal to activate this system constitute a trespass to chattels? Trespass to chat­tels has traditionally required a physical touching of the property. See Restatement (Second) of Torts §217 and Comment e (1963 and 1964); Dobbs, supra, at 123. In recent years, courts have wrestled with the application of this old tort in cases involving unwanted electronic contact with com­puter systems, and some have held that even the transmis­sion of electrons that occurs when a communication is sent from one computer to another is enough. See, e. g., Com­puServe, Inc. v. Cyber Promotions, Inc. 962 F. Supp. 1015, 1021 (SD Ohio 1997); Thrifty-Tel, Inc. v. Bezenek, 46 Cal. App. 4th 1559,1566, n. 6, 54 Cal. Rptr. 2d 468, 473, n. 6 (1996). But may such decisions be followed in applying the Court’s trespass theory? Assuming that what matters under the Court’s theory is the law of trespass as it existed at the time of the adoption of the Fourth Amendment, do these recent *427decisions represent a change in the law or simply the applica­tion of the old tort to new situations?

IV

A

The Katz expectation-of-privacy test avoids the problems and complications noted above,- but it is not without its own difficulties. It involves a degree of circularity, see Kyllo, 533 U. S., at 34, and judges are apt to confuse their own ex­pectations of privacy with those of the hypothetical reason­able person to which the Katz test looks. See Minnesota v. Carter, 525 U. S. 83, 97 (1998) (Scalia, J., concurring). In addition, the Katz test rests on the assumption that this hy­pothetical reasonable person has a well-developed and stable set of privacy expectations. But technology can change those expectations. Dramatic technological change may lead to periods in which popular expectations are in flux and may ultimately produce significant changes in popular atti­tudes. New technology may provide increased convenience or security at the expense of privacy, and many people may find the tradeoff worthwhile. And even if the public does not welcome the diminution of privacy that new technology entails, they may eventually reconcile themselves to this de­velopment as inevitable.6

On the other hand, concern about new intrusions on pri­vacy may spur the enactment of legislation to protect against these intrusions. This is what ultimately happened with re­spect to wiretapping. After Katz, Congress did not leave it to the courts to develop a body of Fourth Amendment case law governing that complex subject. Instead, Congress promptly enacted a comprehensive statute, see 18 U. S. C. *428§§2510-2522 (2006 ed. and Supp. IV), and since that time, the regulation of wiretapping has been governed primarily by statute and not by case law.7 In an ironic sense, although Katz overruled Olmstead, Chief Justice Taft’s suggestion in the latter case that the regulation of wiretapping was a mat­ter better left for Congress, see 277 U. S., at 465-466, has been borne out.

B

Recent years have seen the emergence of many new de­vices that permit the monitoring of a person’s movements. In some locales, closed-circuit television video monitoring is becoming ubiquitous. On toll roads, automatic toll collection systems create a precise record of the movements of motor­ists who choose to make use of that convenience. Many mo­torists purchase cars that are equipped with devices that permit a central station to ascertain the car’s location at any time so that roadside assistance may be provided if needed and the car may be found if it is stolen.

Perhaps most significant, cell phones and other wireless devices now permit wireless carriers to track and record the location of users — and as of June 2011, it has been reported, there were more than 322 million wireless devices in use in the United States.8 For older phones, the accuracy of the location information depends on the density of the tower net­work, but new “smart phones,” which are equipped with a GPS device, permit more precise tracking. For example, when a user activates the GPS on such a phone, a provider is able to monitor the phone’s location and speed of move­ment and can then report back real-time traffic conditions after combining (“crowdsourcing”) the speed of all such *429phones on any particular road.9 Similarly, phone-location-­tracking services are offered as “social” tools, allowing consumers to find (or to avoid) others who enroll in these services. The availability and use of these and other new devices will continue to shape the average person’s expecta­tions about the privacy of his or her daily movements.

V

In the precomputer age, the greatest protections of pri­vacy were neither constitutional nor statutory, but practical. Traditional surveillance for any extended period of time was difficult and costly and therefore rarely undertaken. The surveillance at issue in this case — constant monitoring of the location of a vehicle for four weeks — would have required a large team of agents, multiple vehicles, and perhaps aerial assistance.10 Only an investigation of unusual importance could have justified such an expenditure of law enforcement resources. Devices like the one used in the present case, however, make long-term monitoring relatively easy and cheap. In circumstances involving dramatic technological change, the best solution to privacy concerns may be legisla­tive. See, e.g., Kerr 805-806. A legislative body is well situated to gauge changing public attitudes, to draw detailed *430lines, and to balance privacy and public safety in a compre­hensive way.

To date, however, Congress and most States have not enacted statutes regulating the use of GPS tracking technol­ogy for law enforcement purposes. The best that we can do in this case is to apply existing Fourth Amendment doctrine and to ask whether the use of GPS tracking in a particular case involved a degree of intrusion that a reasonable person would not have anticipated.

Under this approach, relatively short-term monitoring of a person’s movements on public streets accords with expec­tations of privacy that our society has recognized as reason­able. See Knotts, 460 U. S., at 281-282. But the use of longer term GPS monitoring in investigations of most of­fenses impinges on expectations of privacy. For such of­fenses, society’s expectation has been that law enforcement agents and others would not — and indeed, in the main, sim­ply could not — secretly monitor and catalogue every single movement of an individual’s car for a very long period. In this case, for four weeks, law enforcement agents tracked every movement that respondent made in the vehicle he was driving. We need not identify with precision the point at which the tracking of this vehicle became a search, for the line was surely crossed before the 4-week mark. Other cases may present more difficult questions. But where un­certainty exists with respect to whether a certain period of GPS surveillance is long enough to constitute a Fourth Amendment search, the police may always seek a warrant.11 *431We also need not consider whether prolonged GPS monitor­ing in the context of investigations involving extraordi­nary offenses would similarly intrude on a constitutionally protected sphere of privacy. In such cases, long-term track­ing might have been mounted using previously available techniques.

* * *

For these reasons, I conclude that the lengthy monitoring that occurred in this case constituted a search under the Fourth Amendment. I therefore agree with the majority that the decision of the Court of Appeals must be affirmed.