In a narrowly-drawn majority opinion, the United States Supreme Court ruled in United States v. Antoine Jones that the Government’s attachment of a GPS-tracking device to a vehicle, and the subsequent monitoring of the movements of that vehicle on public streets, constitutes a search. Because the Government conceded in the case that it did not comply with the warrant that it had obtained, and argued on appeal only that a warrant was not required to engage in the installation and tracking, Justice Scalia’s opinion lost little time in upholding the ruling of the United States Court of Appeals for the District of Columbia Circuit (captioned below, United States v. Maynard) that the evidence gained via the tracking of a drug suspect had to be suppressed.

The GPS-tracking issue reminds us once again, that technology leads, and the law struggles to follow. Despite the unanimous result, the Justices were not in agreement on why GPS installation and tracking constitute a search under the Fourth Amendment. The respective opinions will provide plenty of fodder for discussion over the Justices’ views of the Fourth Amendment in criminal cases. And likely, it will spark discussion of the Justices’ views of privacy in the civil context, particularly where new technologies are being utilized.

Justice Scalia’s majority opinion, joined by Justices Roberts, Kennedy and Thomas, focused on the language of the Fourth Amendment, that expresses the “right of the people to be secure in their persons, houses, paper, and effects, against unreasonable searches and seizures….” An automobile is an “effect,” the Court ruled, and the attachment of the device and subsequent tracking constituted a search, because “the Government physically occupied private property for the purpose of obtaining information.” Justice Scalia stressed the 18th Century roots of the Fourth Amendment in concepts of physical trespass, while at the same time appearing to question the “reasonable expectation of privacy” jurisprudence that developed in technical eavesdropping and wiretapping cases such as Katz v. United States (U.S. 1967).

Justice Scalia declined to take up the rationale that supported the ruling of the D.C. Circuit – that GPS tracking over a month-long period was constitutionally offensive, while tracking over a shorter period might not be. The D.C. Circuit opinion, relying on Katz v. United States and its “reasonable expectation of privacy” analysis, expressed what is being referred to by commentators as the “mosaic theory.” The reasoning is that tracking over a significant period of time, even though the GPS device is tracking an individual’s movements in public, rises to the level of a privacy violation because the sustained tracking can reveal information that is not apparent as a result of short-term tracking.

Justice Sotomayor concurred in the majority opinion, but wrote separately to, among other things, write supportively of the “reasonable expectation of privacy” jurisprudence that Justice Scalia seemed to reject, or at least be attempting to marginalize. On the contrary, Justice Sotomayor’s concurrence engaged the very arguments that Justice Scalia’s opinion was determined to avoid: The effect of technology on the public’s reasonable expectations of privacy, and the potential for Government abuse of information-gathering technology. Justice Sotomayor’s most telling comment-to-watch in future Internet-related privacy cases:

More fundamentally, it may be necessary to reconsider the premise that an individual has no reasonable expectation of privacy in information voluntarily disclosed to third parties. E.g., Smith, 442 U. S., at 742; United States v. Miller, 425 U. S. 435, 443 (1976). This approach is ill suited to the digital age, in which people reveal a great deal of information about themselves to third parties in the course of carrying out mundane tasks. People disclose the phone numbers that they dial or text to their cellular providers; the URLs that they visit and the e-mail addresses with which they correspond to their Internet service providers; and the books, groceries, and medications they purchase to online retailers. Perhaps, as JUSTICE ALITO notes, some people may find the “tradeoff” of privacy for convenience “worthwhile,” or come to accept this “diminution of privacy” as “inevitable,” ***  and perhaps not. I for one doubt that people would accept without complaint the warrantless disclosure to the Government of a list of every Web site they had visited in the last week, or month, or year. But whatever the societal expectations, they can attain constitutionally protected status only if our Fourth Amendment jurisprudence ceases to treat secrecy as a prerequisite for privacy. I would not assume that all information voluntarily disclosed to some member of the public for a limited purpose is, for that reason alone, disentitled to Fourth Amendment protection.

Justice Alito, joined by Justices Ginsburg, Breyer and Kagan, declined to sign on to the majority opinion and concurred only in the judgment. In contrast to Justice Scalia’s 18th-Century-centric analysis, Justice Alito engaged the issues that are presented by the use of tracking technologies, not only in criminal cases but generally. His opinion was much more receptive to the “mosaic theory” expressed in the Court of Appeals ruling: that while limited tracking may not violate an individual’s privacy, sustained tracking may cross the line. This is a disagreement that was telegraphed to some extent in the oral argument in United States v. Jones.

Justice Scalia’s and Justice Alito’s respective views on how new technologies must be considered also echo their similar diametric divide in Brown v. Entertainment Merchant’s Association (U.S. 2011). In Brown, the Justices agreed that video games are entitled to First Amendment protection, with Justice Scalia writing for the majority, that a video game is no different than a book. Justice Alito agreed with the result in Brown but suggested in a concurring opinion that video games are not the same as books, and that in the future. consideration would have to be given to the impact that this new technology might have on constitutional values.

Justice Alito takes a similar approach in United States v. Jones to his view in Brown. Although a point-by-point analysis of his opinion is beyond the scope of this blog post, it should be required reading (along with all the opinions in Jones) for technology lawyers interested in the attitude of the nation’s highest court toward developments in technology. Justice Alito argues for the “reasonable expectations of privacy” test, although recognizing the challenge that test may present in a world in which smartphone GPS tracking, closed circuit video monitoring, toll-road electronic and other electronic tracking may have on such expectations.

We’ll close with this quotation from Justice Alito’s concurring opinion in Brown v. Entertainment Merchants Association, expressing sentiments that easily could find a place in his most recent opinion in Jones:

In considering the application of unchanging constitutional principles to new and rapidly evolving technology, this Court should proceed with caution. We should make every effort to understand the new technology. We should take into account the possibility that developing technology may have important societal implications that will become apparent only with time. We should not jump to the conclusion that new technology is fundamentally the same as some older thing with which we are familiar.