Privacy Expectations in the Use of GPS Tracking Devices: United States v. Maynard, No. 1:05-cr-00386-ESH-10 (Aug. 6, 2010)
The recent D.C. Circuit Court decision United States v. Maynard (PDF) is one in a series of Circuit Court decisions addressing the legality of federal authorities monitoring a citizen using a GPS tracking device without obtaining a warrant. Unlike previous decisions in the 9th, 8th, and 7th Circuits finding that the Fourth Amendment does not limit federal authorities’ ability place a GPS tracking device on a vehicle without a warrant, the D.C. Circuit Court rejected the use of such tracking devices for continuous and prolonged periods of time without a warrant. The Maynard court concluded that because the Fourth Amendment requires a warrant for private information, and because the sum of information garnered from GPS tracking is outside the scope of public view, federal authorities must obtain a warrant for using GPS tracking devices. In about a month following this ruling, the Department of Justice has urged the Maynard court to reverse its decision.
The facts in Maynard involve the owner, Jones, and manager, Maynard, of a nightclub in Washington, D.C. who were charged with and convicted of conspiracy for cocaine to distribute and to possess with intent to distribute. On appeal, Jones and Maynard raised several joint issues (none of which warranted reversal), but Jones also individually argued that “the [district] court erred in admitting evidence acquired by the warrantless use of a Global Positioning System (GPS) device to track his movements continuously for a month.” The Circuit Court was therefore faced with the following issues: (i) whether the continuous use of the GPS tracking device constituted a “search” under the Fourth Amendment, and (ii) if so, whether the search was “unreasonable.”
Continuous, 24 hour a day GPS Tracking for Four Weeks is Distinguishable from Knotts and Constitutes a Search for Purposes of the Fourth Amendment
The Maynard court distinguished its ruling from previous Circuit Court precedent similarly addressing the issue of GPS tracking and reasonable search under the Fourth Amendment. In each of these preceding cases, the plaintiffs all conceded United States v. Knotts, 460 U.S. 276 (1983) (holding that “the use of a beeper device to aid in tracking a suspect to his drug lab was not a search”) as binding precedent. The Supreme Court in Knotts explicitly reserved the question of whether surveillance for extended periods of time constituted a search. None of the previous Circuit Court decisions had the opportunity to address this issue. As such, the issues in these prior cases questioned whether the discrete act of placing the GPS tracking device on the plaintiff’s car was an unreasonable search. For example, in the 9th Circuit case, this line of reasoning provoked Kozinsiki, in dissent, to say: “Whatever else one may say about Pineda-Moreno, it’s perfectly clear that he did not expect—and certainly did not consent—to have strangers prowl his property in the middle of the night and attach electronic tracking devices to the underside of his car. No one does.”
Common to “each of these three cases,” as the D.C. Circuit Court observed, is that “the court expressly reserved the issue it seems to have thought the Supreme Court had reserved in Knotts, to wit, whether ‘wholesale’ or ‘mass’ electronic surveillance of many individuals requires a warrant.” By contrast to these cases, in Maynard, Jones did not concede Knotts as binding precedent. Consequently, the D.C. Circuit Court thereby proposed an alternate theory of search distinguishing from the reasoning in Knotts. In distinguishing Knotts, the Circuit Court emphasized two main points: (1) that the GPS device was used “to track Jones’s movements 24 hours a day for 28 days as he moved among scores of places” and that (2) in so doing, the authorities were “thereby discovering the totality and pattern of his movements from place to place to place.” As such, the Court concluded that the use of the GPS device did constitute a search because it revealed private information through patterns of behavior, and that the search was unreasonable because individuals have a reasonable expectation of privacy in the sum total of their movements over the period of a month.
Locations Garnered from 24 Hour a Day, Four Week Long Tracking are Not Actually or Constructively Publically Exposed Information and Therefore Such Tracking Constitutes a Search for Fourth Amendment Purposes
The Maynard court acknowledged that the test for reasonableness under the Fourth Amendment often seems “circular, and hence subjective and unpredictable” (citing Kyllo’s description of Katz test). Notwithstanding, the court insisted that at least “[t]his much is clear . . . : Whether an expectation of privacy is reasonable depends in large part upon whether that expectation relates to information that has been ‘expose[d] to the public’” (citing Katz). As such, the Maynard court asked whether and how much information is “expose[d] to the public” in the course of a 24 hour a day, four week tracking of an individual’s movements. Not only, the court concluded, are individual movements over a 24 hour period not actually exposed to the public (“the likelihood anyone will observe all these movements is effectively nil”), neither are they constructively exposed to the public (“the whole of one’s movements . . . reveals more—sometimes a great deal more—than does the sum of its parts”).
The Government in this case argued, citing Knotts, that the information “a person knowingly exposes to this public . . . is not a subject of Fourth Amendment protection.” Because the police could have followed Jones’s every move over public roads for the course of a month, the Government concluded that the information gathered from the GPS tracking device was public. However, the Marynard court rejected this argument saying, citing Katz, the test for “whether something is ‘exposed’ to the public . . . ask[s] not what another person can physically and may lawfully do but rather what a reasonable person expects another might actually do” (emphasis added). Merely because the police could have followed Jones’s movements on public roads, this in no way translates to what a stranger would actually do. It is barely possible, the court reasoned, that a stranger would see the sum total of Jones’s movements over the course of a month. The court wrote:
It is one thing for a passerby to observe or even to follow someone during a single journey as he goes to the market or returns home from work. It is another thing entirely for that stranger to pick up the scent again the next day and the day after that, week in and week out, dogging his prey until he has identified all the places, people, amusements, and chores that make up that person‘s hitherto private routine.
Though the Government did not present the possibility that even if Jones’s movements were not actually exposed to the public they were constructively exposed, the court addressed and rejected this argument as well. Because each of Jones’s movements during the month-long tracking was individually exposed to the public, it could have been argued that his movements were “constructively exposed because each of his individual movements during that time was itself in public view.” However, the Maynard court, citing DOJ v. Reporters Committee, rejected this claim, emphasizing the role of privacy: “When it comes to privacy, however, precedent suggests that the whole may be more revealing than the parts.” The court concludes:
The difference is not one of degree but of kind, for no single journey reveals the habits and patterns that mark the distinction between a day in the life and a way of life, nor the departure from a routine that, like the dog that did not bark in the Sherlock Holmes story, may reveal even more.”
The Maynard court bolstered its finding that the sum of an individual’s movements over the course of a month can reveal otherwise unrevealed private information by citing national security information cases in which the Government made similar arguments (CIA v. Sims, J. Roderick MacArthur Foundation v. F.B.I). Under this so-called “mosaic theory” of information, the Government has conceded that, as the Maynard court describes, “[p]rolonged surveillance reveals types of information not revealed by short-term surveillance, such as what a person does repeatedly, what he does not do, and what he does ensemble.” The Maynard court also cites findings by other courts acknowledging that “prolonged surveillance of a person’s movement may reveal an intimate picture of his life” (Galella v. Onassis, People v. Weaver, State v. Jackson). Extended monitoring of an individual’s movement is not something individuals expect anyone else to do, and if an individual were to perform such monitoring, it would reveal far more than an individual knowingly exposed to the public by traveling on public roads.
An Expectation of Privacy in the Aggregate of One’s Personal Movements Over the Course of a Month is Reasonable According to Societal Expectations
The Maynard court then turned to the question of whether Jones’s expectation of privacy in the aggregation of his movements over the course of a month was reasonable. Though the Maynard court agreed with the Government’s assertion that there is a greater expectation of privacy within the “the sanctity of the home” (Kyllo) than outside the home, this does not mean that “[a] person . . . leave[s] privacy behind when he walks out his front door.” Instead, citing Katz again, the court stated that Fourth Amendment protects “what [one] seeks to preserve as private, even in an area accessible to the public.” As evidence of such societal understandings of privacy, the court cited recent legislative initiatives by some states, including California, Pennsylvania, Florida, Utah, Minnesota, Oklahoma, and South Carolina, that have made it unlawful for authorities to use an electronic device to track the movements of an individual without the individual’s knowledge. Though not conclusive, the Maynard court suggested that “these state laws are indicative that prolonged GPS monitoring defeats an expectation of privacy that our society recognizes as reasonable.” As such, in the case of continuous GPS tracking, even of movements that take place outside the home, because “[s]ociety recognizes Jones’s expectations of privacy . . . as reasonable, . . . the use of the GPS device to monitor these movements defeated that reasonable expectation.”
Implications for Other GPS-Garnered Location Information: Can’t Law Enforcement Just Track Using GPS Information from Smart Phones?
At stake in this ruling is whether the government can lawfully obtain information about the sum total movements of an individual over a prolonged period without a warrant. As with most aggregations of information where the individual pieces of information, on their own, would be meaningless, when taken together these pieces reveal patterns of information that convey more than the individual pieces. As such with the aggregation of an individual’s movements over a prolonged period: previously private information, in which our society recognizes an expectation of privacy, becomes public. In the case of GPS tracking devices, this private-turned-public information thereby is made available to authorities without a warrant.
While the Maynard court described this kind of transition from discrete public movements to an aggregation of private information as a difference in kind rather than degree, some critics question where the line is between discrete tracking and prolonged surveillance: for example, an individual’s habits and patterns of information reveal themselves under different timelines (e.g., a student versus a office worker), so how would law enforcement know, before actually reaching the threshold where an individual’s privacy has been breached, when patterns of behavior, instead of discrete acts, are being revealed? Though this is a fair concern, this author wonders if an unclear threshold is as crippling as some critics seem to think. For example, Maynard does not suggest an absolute bar against the use of GPS tracking devices; rather, the court asserts that, in cases where law enforcement anticipates using a GPS tracking device for continuous monitoring over a prolonged period of time, a warrant is required. Discretion in “how long is too long” seems, at the moment, to be up to the courts, though it could, with more widespread legislation on the issue of warrants and GPS tracking devices, be up to the legislators.
Furthermore, a legislative solution to this question of GPS tracking seems timely given the large swath of the population currently using smart phones with GPS tracking enabled. There have already been instances where law enforcement agencies have accessed consumer location information from phone companies without a warrant; GPS information may not be far behind. Given the anticipated rise in use of smart phones, in addition to the reality that GPS tracking on smart phones tracks all personal movement and not merely movement on public roads (we take our phones with us more places than we travel in a motor vehicle), warrantless garnering of such individual information presents troubling consequences.
Overall, Maynard is important because it addresses the question of whether using a technological device in order to monitor movements in such a way that, in the aggregate, this information reveals reasonably private information is prohibited by the Fourth Amendment. It is vital that courts (and plaintiffs in not conceding Knotts as binding precedent) recognize that all tracking devices are not necessarily similar in effect. Tracking a suspect to a lab over public roads by using a beeper device in lieu of visual tracking is different than using an electronic tool that provides a sum total of movements in a car over the course of a month. Especially when the possibility of smart phone GPS data is introduced into the discussion, Kozinski’s dissent seems all the more poignant. The Government in Maynard argued that continuous tracking for a month of an individual’s motor vehicle is lawful without a warrant by attaching a GPS tracker to a vehicle while the vehicle is in a public space. Would they similarly argue that continuous tracking for a month of an individual’s actions is lawful without a warrant by attaching a GPS tracker to an individual’s cell phone when the cell phone was in a public place? That is, essentially, the case with smart phone GPS technology; merely because the GPS service was enabled on an individual’s smart phone for consumer-related reasons does not imply the individual either knew or consented to this information being available to authorities without a warrant.
It will be interesting to see whether the DOJ’s petition for rehearing is granted. If not, a Supreme Court decision on this issue may not be far behind.
- United States v. Maynard (D.C. Circuit opinion) (PDF)
- “D.C. Circuit Introduces ‘Mosaic Theory’ Of Fourth Amendment, Holds GPS Monitoring a Fourth Amendment Search” (The Volokh Conspiracy)
- “GPS Tracking and a ‘Mosaic Theory’ of Government Searches” (Cato Institute)
- “Appeals Court Rules Against Secret Police GPS Tracking” (Wired Threat Level Blog)
- “Court Rejects Warrantless GPS Tracking” (EFF)
- Feds: Privacy Does Not Exist in ‘Public Places'” (Wired Threat Level Blog)
- “Caught Spying on Student, FBI Demands GPS Tracker Back” (Wired Threat Level Blog)
- “Judge Kozinski Doesn’t Track with the Ninth Circuit on GPS and Fourth Amendment: Calls His Fellow Judges “Cultural Elitists” When it Comes to Privacy” (Above The Law)
- “Feds ‘Pinged’ Sprint GPS Data 8 Million Times Over A Year” (Wired Threat Level Blog)
- “Court OKs Warrantless Cell-Site Tracking” (Wired Threat Level Blog)
- “New ACLU Report and Web Hub Reveal Rise in Political Spying Across United States” (ACLU)
- Policing Free Speech: Police Surveillance and Obstruction of First Amendment-Protected Activity (ACLU) (PDF)