June 12, 2017

Your Vanishing Location Privacy: Why the Supreme Court is Giving Wireless Networks a Look

Written By

Editor’s Note: Victoria Allen is a 2017 Summer Associate with SKO.

The digital age has ushered in a multitude of location mechanisms, triggered by the tap of a fingertip on a communication device. Anyone who has paid roaming fees knows their phone connects to more networks than just those designated by their wireless provider.

Cellphones work by establishing a connection with cell towers. Each tower projects unique directional signals, so a cell phone picking up a signal from the north has distinct CSLI, or cell site location information, from a signal broadcast from the same tower’s southern sector. As they manage their networks, carriers record these connections.

As cellular networks march toward a 5G future with thousands of new “microsites” with smaller coverage areas, CSLI rivals GPS as a way to nearly pinpoint a device’s location. This may be a boon to law enforcement agencies searching for suspects, but on June 5 the U.S. Supreme Court decided to take a closer look at privacy issues associated with the technology.

In thousands of cases each year, law enforcement agencies obtain the CSLI associated with suspects’ phones under the Stored Communications Act, instead of securing a search warrant based on probable cause. This “tower dump” can reconstruct a suspect’s location and movements over time, and is effective in crime solving. Nearly all federal courts have agreed getting a tower dump from cellular providers does not require a warrant. As recently as 2015 the Supreme Court declined to review any of those decisions.

But last week the Court granted a defendant’s request to review his conviction upheld last year by the Sixth Circuit Court of Appeals in USA v. Timothy Carpenter.

The Court will consider whether the warrantless seizure and search of cellphone records revealing Carpenter’s location and movements over 127 days violated his 4th Amendment protection from unreasonable searches and seizures. Carpenter was nabbed by the FBI in a string of armed robberies at Radio Shacks and T-Mobile stores around southeastern Michigan and northwestern Ohio. After receiving a judge’s order to obtain records from wireless carriers, the FBI determined that Carpenter had been less than two miles from each store when the robberies took place. A Michigan jury convicted Carpenter and co-defendants, and a district judge sentenced him to multiple 25-year terms. The sentence was affirmed last year and Carpenter filed for Supreme Court review, even though two terms ago the Court declined to review a nearly identical decision from the Eleventh Circuit.

The Court’s decision to grant certiorari now raises two questions. Although every Circuit court that considered the question said no warrant is required to obtain CSLI from a carrier, why is the Supreme Court accepting a case that is not a Circuit splitting issue? Why would the Court grant cert to Carpenter v. U.S., when it denied U.S. v. Davis, which presented almost the same issue and fact pattern two years ago? 

Ironically, one clue may lie in an earlier decision from the court that affirmed Carpenter’s sentence after rejecting his 4th Amendment claim. In 2010, the Sixth Circuit found government agents violated the 4th Amendment with a warrantless search of email, saying ”the 4th Amendment must keep pace with the inexorable march of technological progress, or its guarantees will wither and perish.” In the context of wireless communication, this march of progress involves the proliferation of carrier-controlled microcells that create increasingly granular location information.

Why answer an unasked question?

We have written previously about why courts have generally held a warrant is not required to access cell site location information. The privacy protection provided by the 4th Amendment guards individuals against unreasonable searches and seizures by law enforcement. Reasonableness is grounded in whether the person asserting the protection has an actual expectation of privacy that society will recognize.

But the Supreme Court has held that parties lack an expectation of privacy in business records created by 3rd parties, like a telephone company that records the numbers dialed to initiate a call. Courts don’t treat the review of most 3rd party transactional records as a search at all.

These principles, though developed in a different technology era, remain in use today. Regarding cellphone network data for geo-location, the records have not triggered the same level of privacy protection as more direct methods of surveillance, like a hidden tracking device.

To fill the gap between 4th Amendment protection and no protection at all, Congress created the Stored Communications Act (SCA), which requires that the government present “reasonable grounds” but not “probable cause” to obtain records like CSLI. Whether such information is also protected by the 4th Amendment has become a more difficult question as transactional records become more numerous and more capable of revealing seemingly private information.

The aging doctrine that makes appellate judges uncomfortable

So, why did the Supreme Court accept Carpenter’s petition after declining the factually similar case U.S. v. Davis?

Shortly after the Court denied review in Davis, the Fourth Circuit Court of Appeals reversed a panel decision holding that access to CSLI requires a warrant.  In U.S. v. Graham, the Court chose not to contradict Supreme Court precedent on 3rd- party doctrine which “mandate[d]” its conclusion.

Three judges dissented, finding it difficult to apply the 3rd-party doctrine when the data involved was a pervasive 221 days’ of information and about 29,000 location data points per defendant. The dissenters also questioned whether the doctrine applies to data not “voluntarily conveyed” by cell phone users, because conveyance is a “necessary analytical component” in 3rd-party doctrine cases from the Supreme Court. In the earliest case involving phone networks, the information voluntarily conveyed was the number dialed by a suspect. In contrast, cellphone users don’t so directly influence which cell tower their phone connects to.

The Court’s decision to review Carpenter’s claims related to CSLI, validates concern that the 4th Amendment is being browbeaten into retreat by the swell of information that is conveyed to 3rd parties. The Court’s decision to hear Carpenter is an indication that the Supreme Court is ready to reconsider that decades old 3rd-party doctrine. 

And it may be time.