Score One For The 4th Amendment: Appeals Court Says Police Need A Warrant To Track Phone Users' Location

from the big-win dept

A very big and important ruling came out yesterday in the 11th Circuit appeals court, saying that police need to get a warrant to track someone's location (via their mobile phone locations). This is a big deal, as we've been discussing for years. Many state courts have issued similar rulings, but many federal courts had gone the other way. While a few district courts had agreed that a warrant was needed, having an appeals court say so is a big deal.

In this case, the defendant, Quartavius Davis, was accused of a bunch of crimes, involving robbing a bunch of stores. Among the variety of evidence against him was cell phone location data -- specifically 11,606 location records. Davis argued that the data was collected without a warrant, violating his 4th Amendment rights (he also has other issues with the way the case was handled and challenges some other aspects as well, but we'll focus on the 4th Amendment issue concerning his location data). The court notes that other courts are still struggling with this issue, and looks to the Supreme Court's famous ruling in the Jones case, involving whether or not a warrant is needed to attach a GPS device to a car. As we noted then, that ruling stopped short of really examining if gathering up location data required a warrant, though some of the side opinions (mainly the concurrence by Justice Sotomayor) discussed the idea. This ruling looks back at some history around the 4th Amendment, and the evolving view concerning "trespass theory" vs "privacy theory," before digging into Jones. The Jones case, you may recall, was decided on the idea that putting the device on the car was a form of "trespass," leaving aside the privacy aspect. But, obviously, this case is different. Thankfully, the court takes some instruction from the concurrences that do discuss privacy theory, and see how they apply in this case.

But, in an important way, the court seems to go even further. While much of the focus in the Jones case was on the "mosaic theory" of linking together a bunch of individual location data points to create a picture that reveals something people expected to be kept private, this ruling notes that even a single data point may be enough to violate the expectation of privacy:

One’s cell phone, unlike an automobile, can accompany its owner anywhere. Thus, the exposure of the cell site location information can convert what would otherwise be a private event into a public one. When one’s whereabouts are not public, then one may have a reasonable expectation of privacy in those whereabouts. Therefore, while it may be the case that even in light of the Jones opinion, GPS location information on an automobile would be protected only in the case of aggregated data, even one point of cell site location data can be within a reasonable expectation of privacy. In that sense, cell site data is more like communications data than it is like GPS information. That is, it is private in nature rather than being public data that warrants privacy protection only when its collection creates a sufficient mosaic to expose that which would otherwise be private.

The court also rejects the idea that the information is not private just because it puts the defendant near the scene of a crime:

The prosecutor at trial stressed how the cell phone use of the defendant established that he was near each of six crime scenes. While committing a crime is certainly not within a legitimate expectation of privacy, if the cell site location data could place him near those scenes, it could place him near any other scene. There is a reasonable privacy interest in being near the home of a lover, or a dispensary of medication, or a place of worship, or a house of ill repute. Again, we do not see the factual distinction as taking Davis’s location outside his expectation of privacy. That information obtained by an invasion of privacy may not be entirely precise does not change the calculus as to whether obtaining it was in fact an invasion of privacy.

And, finally, the court addresses the famed "third party doctrine" issue, of whether or not Davis gave up his right to privacy to this information because it's been "given" to a third party (i.e., the mobile phone operators). The court is not convinced and (thankfully) explains how Smith v. Maryland (that key case that so many third party doctrine claims rely on) doesn't make sense here, relying on a ruling from the 3rd Circuit, stating that because Davis did not "voluntarily" shared this information with the mobile operator, the third party doctrine does not apply (amusingly, the court even cites the government's own arguments to support the lack of a voluntary handover):

The reasoning in Smith depended on the proposition that “a person has no legitimate expectation of privacy in information he voluntarily turns over to third parties,” .... The Third Circuit went on to observe that “a cell phone customer has not ‘voluntarily’ shared his location information with a cellular provider in any meaningful way.” That circuit further noted that “it is unlikely that cell phone customers are aware that their cell phone providers collect and store historical location information.” ... (emphasis added). Therefore, as the Third Circuit concluded, “when a cell phone user makes a call, the only information that is voluntarily and knowingly conveyed to the phone company is the number that is dialed, and there is no indication to the user that making that call will also locate the caller.” ... Even more persuasively, “when a cell phone user receives a call, he hasn’t voluntarily exposed anything at all.” ....

Supportive of this proposition is the argument made by the United States to the jury. The prosecutor stated to the jury “that obviously Willie Smith, like [Davis], probably had no idea that by bringing their cell phones with them to these robberies, they were allowing [their cell service provider] and now all of you to follow their movements on the days and at the times of the robberies . . . .” Just so. Davis has not voluntarily disclosed his cell site location information to the provider in such a fashion as to lose his reasonable expectation of privacy. In short, we hold that cell site location information is within the subscriber’s reasonable expectation of privacy. The obtaining of that data without a warrant is a Fourth Amendment violation.

That said, the court still decides to not overturn the original ruling, saying that the court ruled in good faith. However, it still means that future cases will require a warrant for this information (within areas covered by the 11th Circuit). It seems likely that this, or another similar case in a different circuit, will eventually make it to the Supreme Court, but this is a very good ruling in the meantime.

Filed Under: 11th circuit, 4th amendment, cell site location data, gps, jones, location data, mosaic theory, privacy, quartavius davis, third party doctrine, warrant