I have served on this court for nearly three decades. I regret that over that time the courts have gradually but deliberately reduced the protections of the Fourth Amendment to the point at which it scarcely resembles the robust guarantor of our constitutional rights we knew when I joined the bench.

Sound like something departing Supreme Court Justice John Paul Stevens could have written?  Not quite; it’s the dissenting opinion of Judge Reinhardt in a denial of en banc consideration by, of all places, the 9th Circuit, from a decision they made in January in US v. Pineda-Moreno. 

Technology has always given courts fits in 4th Amendment cases.  The first time the Supreme Court looked at wiretapping, way back in 1928, it decided that there wasn’t a problem because the wires being tapped belonged to the telephone company, and the defendant thus didn’t have a property interest what the government was “seizing.”  It wasn’t until 40 years later that the court focused instead on a person’s expectation of privacy in their phone conversations and held that wiretapping did implicate 4th Amendment concerns.  In recent years, the courts have had to tackle a wide variety of other gadgetry, from infrared sensors to helicopter overflights to cell phones.

The Supreme Court first confronted the use of devices to monitor vehiclular movment in United States v. Knotts in 1982, and held that the police use of a beeper to track a vehicle doesn’t constitute a “search” because “a person traveling in an automobile on a public thoroughfare has no reasonable expectation of privacy in his movements from one place to another.” 

The Pineda-Moreno court relied on that same analysis, and went it one better.  On two occasions, in order to place the GPS tracker, the police had to sneak onto his driveway at 4:00 in the morning.  No problem, said the court, since the driveway had no gate or “no trespassing” signs; “because Pineda-Moreno did not take steps to exclude passersby from his driveway, he cannot claim a reasonable expectation of privacy in it.”  Since the device was placed on the outside of his vehicle, he had no reasonable expectation of privacy there, either.  And as for monitoring his whereabouts, the device gave the police the same information they could have obtained by simply following him. 

To me, this deconstructionist view of privacy expectations misses the entire point of the 4th Amendment.  The Amendment is intended as a bulwark against government action, and the central question should be, what is the reasonable expectation of privacy with regard to the government, not with the public as a whole.  If I park my car in a driveway, I might not have a reasonable expectation that some kid isn’t going to come onto the driveway and crawl under the car to retrieve an errant ball, but that doesn’t mean I should expect that police officers will crawl onto the driveway in the dead of night and affix a device with which they can track my movements.  Similarly, I can reasonably expect that a car following me on the highway can tell where I’m going at that moment, but that’s a far cry from expecting the police to be able to monitor everywhere I go.

Earlier this month, the DC Circuit exposed the flaws in the 9th’s logic in US v. Jones, where the police had used a GPS device to track Jones’ vehicle for a full month.  The court distinguished Knotts by noting that that case had involved the use of a beeper to track an item of contraband from one site to another, and had specifically reserved the issue of whether longer surveillance would require a warrant; in fact, the Knotts opinion cautioned that it should not be read to sanction “twenty-four hour surveillance of any citizen of this country.”   The court then tackled the notion that Jones’ rights weren’t violated because his movements over that period of time were exposed to the public:

Two considerations persuade us the information the police discovered in this case — the totality of Jones‘s movements over the course of a month — was not exposed to the public: First, unlike one‘s movements during a single journey, the whole of one‘s movements over the course of a month is not actually exposed to the public because the likelihood anyone will observe all those movements is effectively nil.  Second, the whole of one‘s movements is not exposed constructively even though each individual movement is exposed, because that whole reveals more — sometimes a great deal more — than does the sum of its parts.

Jones isn’t a complete answer to the questions arising from the use of a GPS device.  It doesn’t address the placement of the device; in fact, the opinion makes no mention of how the device got on Jones’ car in the first place.  And one wonders how the court would have treated a much shorter surveillance, one lasting only a day or two.  The decision is certainly going to be of minimal, if any, value in cases where the police use the device to track a person from one place to another in a short period of time, as was the situation in Knotts.

Still, it’s a massive improvement over Pineda-Moreno.  The New York Court of Appeals had held that notwithstanding Knotts, under the state constitution such tracking required a warrant, concluding that permitting the warrantless use of such devices “would be to countenance an enormous unsupervised intrusion by the police agencies of government upon personal privacy.”  The 9th Circuit shrugged this off:

Should government someday decide to institute programs of mass surveillance of vehicular movements, it will be time enough to decide whether the Fourth Amendment should be interpreted to treat such surveillance as a search.

By that time it might be too late.