Do Police Need a Warrant for GPS Tracking?

In a Time essay, Adam Cohen notes a circuit split on the question of whether police need a warrant to "put a GPS device on the bottom of your car and keep track of everywhere you go." Last January a three-judge panel of the U.S. Court of Appeals for the 9th Circuit unanimously ruled that DEA agents did not violate the Fourth Amendment rights of a suspected marijuana grower by electronically tracking his Jeep, even when they snuck onto his property in the middle of the night to plant a GPS device on the bottom of the car. This month the full court declined to rehear the case, a decision from which Chief Judge Alex Kozinski passionately dissented:

Having previously decimated the protections the Fourth Amendment accords to the home itself, our court now proceeds to dismantle the zone of privacy we enjoy in the home's curtilage and in public. The needs of law enforcement, to which my colleagues seem inclined to refuse nothing, are quickly making personal privacy a distant memory. 1984 may have come a bit later than predicted, but it's here at last….

The modern devices used in Pineda-Moreno's case can record the car's movements without human intervention—quietly, invisibly, with uncanny precision. A small law enforcement team can deploy a dozen, a hundred, a thousand such devices and keep track of their various movements by computer, with far less effort than was previously needed to follow a single vehicle. The devices create a permanent electronic record that can be compared, contrasted and coordinated to deduce all manner of private information about individuals. By holding that this kind of surveillance doesn't impair an individual's reasonable expectation of privacy, the panel hands the government the power to track the movements of every one of us, every day of our lives.

As Cohen notes, Kozinski also objected to the panel's conclusion that the DEA did not need a warrant to enter the suspect's driveway, part of the traditionally protected area around the home known as the "curtilage," because he had not put up a fence. Kozinski suggested this reasoning betrays a class bias:

The very rich will still be able to protect their privacy with the aid of electric gates, tall fences, security booths, remote cameras, motion sensors and roving patrols, but the vast majority of the 60 million people living in the Ninth Circuit will see their privacy materially diminished by the panel's ruling…

There's been much talk about diversity on the bench, but there's one kind of diversity that doesn't exist: No truly poor people are appointed as federal judges, or as state judges for that matter. Judges, regardless of race, ethnicity or sex, are selected from the class of people who don't live in trailers or urban ghettos. The everyday problems of people who live in poverty are not close to our hearts and minds because that's not how we and our friends live. Yet poor people are entitled to privacy, even if they can't afford all the gadgets of the wealthy for ensuring it.

Cohen, who seems surprised to hear such arguments from "a leading conservative, appointed by President Ronald Reagan," notes that "judges appointed by Presidents Ronald Reagan, George W. Bush and Bill Clinton" joined a unanimous decision in which the U.S. Court of Appeals for the District of Columbia Circuit recently concluded that the Fourth Amendment does impose restrictions on the use of GPS devices. The August 6 opinion (PDF) was written by Douglas Ginsburg, another libertarian-leaning Reagan appointee (who, you may recall, missed his shot at the Supreme Court because he smoked pot as an assistant law professor at Harvard in the '70s). Like Kozinski, Ginsburg distinguished GPS tracking from tailing a car with the assistance of a surreptitiously placed radio transmitter ("beeper"), a practice the Supreme Court has said does nor require a warrant:

The Court explicitly distinguished between the limited information discovered by use of the beeper—movements during a discrete journey—and more comprehensive or sustained monitoring of the sort at issue in this case….Most important for the present case, the Court specifically reserved the question whether a warrant would be required in a case involving twenty-four hour surveillance, stating, "if such dragnet-type law enforcement practices as respondent envisions should eventually occur, there will be time enough then to determine whether different constitutional principles may be applicable."

Ginsburg noted that the capabilities of modern tracking technology far outstrip what can feasibly be accomplished by human observers in public:

We hold the whole of a person's movements over the course of a month is not actually exposed to the public because the likelihood a stranger would observe all those movements is not just remote, it is essentially nil. 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.

More on warrantless electronic tracking here, here, and here.

[Thanks to Tricky Vic for the tip.]