On Tuesday, the Supreme Court will hear arguments in one of the most important privacy cases in decades. In United States v. Jones, the Court will decide whether the secret installation by police of a GPS device to the defendant's vehicle and monitoring his movements every day for four weeks is a "search" under the Fourth Amendment that requires a warrant. The case has enormous implications. The decision will affect the ability of law enforcement to employ powerful and highly intrusive surveillance technology to investigate crime without being subjected to constitutional constraints.
In considering the broad and potentially dragnet use of GPS technology at the sole discretion of law enforcement authorities to pry into the details of people's daily lives, one is reminded of Justice Louis Brandeis's famous dissent over eighty years ago in Olmstead v. United States, in which he condemned the government's intrusion into people's privacy with the memorable language that a person has "the right to be let alone -- the most comprehensive of rights and the right most valued by civilized men." The ability of government to use sophisticated surveillance technology to track a person's movements constantly, relentlessly, and indefinitely evokes the specter of the omnipresent Orwellian "Big Brother."
Indeed, such constant surveillance for an unlimited period of time, as the lower court in Jones observed, allows the government to learn with remarkable precision the most intimate details of a person's life, including his or her political, religious, amicable, and amorous associations. Illustrative of the kinds of information this technology could reveal, record, and retain are visits to the abortion clinic, the AIDS treatment center, the psychiatrist, the fitness center, the strip club, the criminal defense attorney, the by-the-hour motel, the mosque, synagogue, and church, the gay bar, and on and on. By using this technology, and drawing reasonable inferences, the government could assemble patterns of a person's personal and professional activities and could easily learn whether a person is a heavy drinker, a weekly church-goer, a regular at the gym, a faithful husband, an associate of a political organization, and an outpatient receiving medical treatment.
The Supreme Court's task is not simple. The Fourth Amendment has been interpreted for the past fifty years to apply only to private areas, not public ones, and to society's reasonable expectations of privacy. Thus, using new technology to acquire information about private matters inside the home would constitute a "search." This was the teaching in Kyllo v. United States, decided ten years ago, in which the Court held that the government's use of a "thermal imager" to detect heat emanating from inside the home is a search and required a warrant. But in another case decided thirty years ago -- United States v. Knotts -- the Court said that attaching a beeper to a vehicle and following the vehicle on a highway is not a search because the activity was conducted in public and anyone could see the car's movements. If the Justices rely on Knotts, then the result is clear; law enforcement will be given a license to use visual surveillance technology to watch every person's movements and activities in public constantly, indefinitely, and without any legal restraints.
But there is no question that the new surveillance technology is vastly different from the primitive beeper in Knotts, both qualitatively and quantitatively. The new technology allows the government easily and cheaply to engage in massive, intrusive, and unlimited surveillance of every citizen any time, any place, and regardless of atmospheric conditions. Several courts have characterized this new technology as one of the greatest threats to privacy, and the consequent need to adjust Fourth Amendment "expectations of privacy" doctrine to this new phenomenon.
It's anybody's guess what the Justices will do. The Justices could affirm the lower court and find that use of GPS constitutes a sufficient threat to privacy to require that law enforcement obtain from a judge a warrant before using it. However, the Justices could also find that GPS merely "enhances" what the police could already see with the naked eye and therefore GPS surveillance is not covered by the Fourth Amendment. To reach this conclusion, however, the Justices would have to concede that for the police to accomplish with the "naked eye" what GPS surveillance accomplishes would require the assignment of hundreds, perhaps thousands of additional police, and the installation of cameras on every street lamp. However, according to several lower courts, GPS is not an enhancement; it "replaces" the human senses, and facilitates a new perception of the world in which any object may be followed and exhaustively recorded for an unlimited period of time.
The Justices could also find that by operating their vehicles in public, people have voluntarily conveyed their travels to the outside world and in effect assumed the risk that they would be followed. This is one of the risks in modern society. However, it seems unreasonable -- even perverse -- to suggest that by living in modern society, people have assumed the risk that they will be "seen" constantly, continuously, and for an unlimited period of time, to have "recorded" all the detailed information of their movements through the world, to have "transmitted" to the government all of the personal data that has been collected, and to have this information "retained" by government for an indefinite and unlimited period of time, all without any judicial oversight or constitutional constraints. My guess is that most members of society would say that they have not assumed these risks, and that it is unreasonable for government to employ this new surveillance technology without first getting a warrant. But will the Supreme Court agree?