Within one week in July, two landmark decisions dealing with cutting edge technology reached vastly different conclusions on the extent of constitutional privacy protections. The New Jersey Supreme Court and the US Court of Appeals for the Fifth Circuit provided different answers to the same question: do police need a search warrant to track a person through his cell phone? New Jersey's high court said yes; the Fifth Circuit said no. These decisions expand the growing rift in courts throughout the country on the constitutionality of an increasingly popular law enforcement tool.
Cell Phone Tracking Explained
In a nutshell, here is the technology the courts were looking at: in order for a cell phone or smartphone to make a call, send a text message or browse the internet, the device must access the cellular provider's telephone network. The phone does that by connecting to cell phone towers installed throughout the country by the providers. When a phone is powered on, it searches for and connects to the nearest tower. As the phone moves, the phone constantly reconnects to the closest tower. Providers keep these records for varying amounts of time, and law enforcement can request the historical records of which towers a phone connected to. Police can also obtain real-time location information by asking the cell phone provider to identify which tower a phone is connected to at any given moment.
As smartphones have taken over the cell phone market, the accuracy of this data has only grown. First, the growing demand for internet connected portable electronic devices has resulted in the installation of more towers. CTIA, the cell phone industry association, reports that between 2000 and 2012 the number of towers in the United States increased from 104,288 to 301,799. Second, more smartphones cause more web traffic, which grew almost four times over from 2010 to 2012. And that ultimately causes more frequent tower connection records. Naturally, police have used this tool with increasing frequency. A coordinated Freedom of Information Act request by the ACLU last year revealed that over 250 different law enforcement agencies across the country have used the technology, relying on different legal standards to access this information.
In turn, the constitutionality of the practice is now being litigated in federal and state courts across the country. Ultimately, the issue really raises two Fourth Amendment questions: whether a person has a reasonable expectation of privacy concerning their physical location and, if so, whether that expectation of privacy exists notwithstanding the fact that the records are held by a third party, specifically the cell phone provider? Courts looking at the issue have reached conflicting opinions on both questions.
Location Privacy: An Exhaustive Snapshot of Movement and Patterns
For many years, two US Supreme Court cases framed the constitutionality of location privacy. First, in United States v. Knotts the Court found no Fourth Amendment violation when police placed a primitive beeper in a can of chloroform and followed the can as it traveled in the suspect's car on public streets. The following year in United States v. Karo, the Supreme Court dealt with a similar situation involving warrantless police tracking of a can of ether. But in Karo, the can travelled not only in public streets, but also was stored in private homes too. Ultimately, Knotts and Karo came to be understood as permitting warrantless tracking in public streets, but not private homes. And of course, the technology was primitive; the beeper had to be closely followed by law enforcement and was only intended to supplement visual surveillance.
In federal courts, public or private remained the dividing line and a warrant was not required for public surveillance, even as technology improved to allow police surveillance in new, unprecedented ways not previously imagined or physically possible, most notably constant, around the clock GPS monitoring. Some state courts, looking at the issue under their state constitutions, had taken a different view, with New York, Oregon and Washington all finding such surveillance even on public streets triggered the warrant requirement.
In 2012, the Supreme Court decided United States v. Jones, which involved warrantless GPS surveillance of a suspected drug dealer in public streets over 28 days. The D.C. Circuit Court of Appeals had found the GPS surveillance unconstitutional because Knotts did not envision this type of prolonged surveillance. Aggregated GPS surveillance of a person's movements over an extended period of time provided a great more detail than a snapshot of individual public movements at a discrete time. Because a person could not reasonably expect that another person might actually discover this aggregated information everywhere they'd gone for almost a month there was necessarily a reasonable expectation of privacy.
The Supreme Court affirmed, but on different grounds. Instead of looking to an expectation of privacy test, it found the government's trespass onto the defendant's private property - the car - for the purpose of obtaining information was a "search" under pre-Katz Fourth Amendment law.
But in two important concurring opinions by Justices Sotomayor and Alito, a majority of the Court signaled its readiness to find a reasonable expectation of privacy to be free from prolonged surveillance. The justices shared the D.C. Circuit's concern with the capabilities of technology to cheaply and efficiently aggregate reams of data to create new and unknown intrusions into previously private places.
Following Jones, federal courts however continued to hew to Knotts and Karo, hesitant to extend concurring opinions into binding precedent. But state courts have been more aggressive on the issue, and both South Dakota and Massachusetts have ruled a person has an expectation of privacy in their public movements, meaning a search warrant is required before a person's location can be tracked. State legislatures have acted too, with Maine and Montana both passing bills requiring police obtain a search warrant before accessing a person's location, and with a number of other states considering similar steps.
In July, the New Jersey Supreme Court reached the same conclusion in State v. Earls. There, police looking for a defendant found him by acquiring, without a search warrant, cellphone tower data from T-Mobile. The state high court found the warrantless acquisition of the data unconstitutional under its state constitution. While Earls involved cell phone tracking, its rationale extends beyond that specific technique and into any form of location-based surveillance that "involves a degree of intrusion that a reasonable person would not anticipate." That is because extensive location information "can reveal not just where people go which doctors, religious services, and stores they visit but also the people and groups they choose to affiliate with and when they actually do so." Since "details about the location of a cell phone can provide an intimate picture of one's daily life," if the police want access to this data, they now must get a search warrant.
Third Party Doctrine: Voluntarily Assuming a Risk?
New Jersey was able to extend this constitutional protection to its citizens because it had previously abolished the major obstacle binding courts, especially federal ones: the "third party doctrine."
In the 1970's, the Supreme Court decided two cases United States v. Miller and Smith v. Maryland that collectively established that a person generally has no expectation of privacy in materials turned over to a third party. These cases involved records far more primitive than cell tower connection records. Miller dealt with a bank's records of a customer's transactions and deposits; Smith involved the phone numbers a person dialed. The doctrine was not at issue in Earls because New Jersey state law had abolished it, meaning individuals still retained their right to privacy in information turned over to third parties. Other states, including California, have done the same.
But in federal court, Smith and Miller have been recited by the government time and again in resisting challenges to warrantless acquisition of a variety of records from Internet and cell phone providers, including cell tower records. The government's argument is simple: the cell tower records belong to the cell provider, not the customer. Once the customer reveals their location to the company in order to have their phone call connected, they have surrendered their Fourth Amendment protection in that data.
While federal district courts have issued conflicting opinions on whether a warrant is required, federal appellate courts have only recently examined the issue. And so far, they have issued conflicting opinions. In 2010, the Third Circuit ruled in In the Matter of the Application of the U.S. For An Order that a warrant may be required to access cell tower records in some instances because "a cell phone customer has not 'voluntarily' shared his location information with a cellular provider in any meaningful way."
But just a week after Earls was decided, the Fifth Circuit ruled in In re: Application of the U.S. for Historical Cell Site Data that a cell phone user has no expectation of privacy in their location because that information is voluntarily turned over when the "user makes a choice to get a phone, to select a particular service provider, and to make a call." Relying on Miller and Smith, the government ultimately did not need a search warrant to access this data.
There is much to quibble with this simplistic understanding of privacy expectations, particularly as the explosion in the breadth of information stored by third party Internet and telephone providers means the narrow third-party exception is threatening to swallow the rule. Even Justice Sotomayor explicitly called out the doctrine in her concurring opinion in Jones, noting it was "ill suited to the digital age, in which people reveal a great deal of information about themselves to third parties in the course of carrying out mundane tasks."
In an age of rapidly changing technology, courts must think about privacy expectations the way that Earls did: by recognizing "changes in technology" affect Fourth Amendment rights because they "affect the level of detail" relayed to law enforcement. In 2001, the US Supreme Court said in Kyllo v. United States that "it would be foolish to contend that the degree of privacy secured to citizens by the Fourth Amendment has been entirely unaffected by the advance of technology." Yet, courts, like the Fifth Circuit, relying on antiquated cases involving primitive technologies like Knotts and Karo or far more limited records like Miller and Smith to defeat constitutional challenges to new forms of electronic surveillance are ignoring the realities of modern technology and its capabilities to reveal far more information about people in easy, convenient ways never before imagined. Like Earls noted, "cell phones are not meant to serve as tracking devices to locate their owners wherever they may be." Cell phones are an integral part of everyday life; courts must require a user do something more than merely turn on phone before finding their constitutional rights have been irretrievably surrendered.
Hanni Fakhoury is a Staff Attorney with the Electronic Frontier Foundation and focuses on criminal law, privacy and free speech litigation and advocacy.
Suggested citation: Hanni Fakhoury, Mixed Signals in Cell Phone Location Decisions, JURIST - Hotline, Sept. 18, 2013, http://jurist.org/hotline/2013/09/hanni-fakhoury-cell-phone.php.
This article was prepared for publication by Michael Muha, an associate editor with JURIST's professional commentary service. Please direct any questions or comments to him at firstname.lastname@example.org