The Government Does Not Need a Warrant to Obtain Cellphone Location Records
Without obtaining a search warrant, can the government find out where you have been during the last few months by tracking the movement of your cellphone? A recent decision of the U.S. Court of Appeals for the Fourth Circuit recognizes that the government has that power.
In one sense, the decision is unsurprising. When you are in a public place, the police can follow you wherever you go. They don't need a warrant to do so because you cannot expect privacy when you are walking on a sidewalk or strolling through a mall. Tracking your cellphone while you are in public may be no different.
But what if you are not in a public place when the government decides to find you? The police can't enter your home to search for you without a warrant. Should the police be entitled to find you in a private location by accessing the last known location of your cellphone without first obtaining a search warrant?
The issue divides those who believe that the needs of law enforcement outweigh privacy interests and those who believe that civil liberties are eroded when the government is allowed to track almost anyone no matter where they go. Cellphones, after all, are ubiquitous. Nearly everyone carries one, making it possible for the government to monitor the movements of almost all Americans. In fact, the Washington Post reports that "the National Security Agency is collecting billions of records a day to track the location of mobile phone users around the world," including the "accidental" collection of cellphone locations within the United States.
Facts of the Graham Case
The government suspected Aaron Graham of participating in a series of armed robberies. To place Graham near the location of the robberies, the government subpoenaed records from Sprint/Nextel that allowed it to determine the location of the cellphone towers that transmitted calls or messages to or from Graham's cellphone. At times, phones "ping" a tower even if no call or message is transmitted, and cellphone companies keep a record of those "pings." The government collected 29,000 data points (pings, texts, and calls) over a period of 221 days that enabled it to map Graham's movements over that time.
The government's theory (which has been the subject of some dispute among experts) was that Graham's phone connected to the nearest tower, placing Graham within two miles of a particular tower at 29,000 different times. Tech-savvy criminals leave their cellphone at home when they commit crimes, but Graham was apparently unaware that he was leaving a trail for the government to follow by carrying his cellphone.
To obtain the records, the government applied to a federal court for an order that required Sprint/Nextel to disclose them. A federal law known as the Stored Communications Act permits a court to enter such an order when the government alleges facts that establish "reasonable grounds" to believe the records are relevant to a criminal investigation. The "reasonable grounds" standard does not require the government to show that the records are likely to lead to evidence of a crime.
Graham's lawyer filed a motion to suppress (or exclude from evidence) the cellphone records on the ground that having "reasonable grounds" to suspect a crime is not a sufficient basis for obtaining records about an individual's movements. Graham's lawyer argued that the order to disclose the records violated the Fourth Amendment, which requires a showing of probable cause to believe a crime was committed before the court can authorize a search of "persons, houses, papers, and effects" when the search intrudes upon an individual's reasonable expectation of privacy.
The Court's Opinion
The three-judge panel that originally heard the case decided by a 2-1 vote that the government's warrantless acquisition of cellphone data violated the Fourth Amendment. The full court then voted to rehear the case en banc.
Most appeals are decided by a panel of three judges selected randomly from all the judges appointed to that circuit. When the court reviews a lower court decision en banc, every court of appeals judge in the circuit participates in the decision. Fifteen judges voted on the en banc decision in the Graham case. The court voted 12-3 that ordering the production of cellphone records without a warrant does not violate the Fourth Amendment.
The court recognized that Supreme Court precedent requires the government to obtain a warrant before using technological devices to track an individual's movement in real time. In 2012, the Supreme Court held that secretly attaching a GPS device to a car and monitoring the car's movements for several weeks constituted a search for which a warrant was required. Since FBI agents trespassed upon the owner's property by attaching the device to the vehicle's undercarriage, they were required to obtain a warrant even if they would not have needed to follow the vehicle as it traveled on public streets.
An earlier case held that the police violated the Fourth Amendment when they placed a beeper in contraband and used the beeper's transmission to follow the contraband into a defendant's home. Concealing the beeper with an informant's consent did not violate the Fourth Amendment, but using it to learn that the contraband was inside the defendant's house was no different than entering the house to look for the contraband, a search that requires the issuance of a warrant.
The court reasoned that the cellphone tracking in Graham's case was different from the use of technology that requires a warrant. The police did not trespass on Graham's property to install tracking technology and they did not necessarily gain data from within the privacy of Graham's own home. Rather, they gathered data from cellphone towers. The court decided that Graham had no reasonable expectation of privacy in that data because he voluntarily allowed Sprint/Nextel to collect it.
The dissent, on the other hand, expressed doubt that cellphone users have any idea how much data their providers collect and store every time they turn on their phones. The dissent also noted that cellphone users do not voluntarily provide location information to their providers. Rather, a tower at a location unknown to the customer pings the customer's phone without the customer's knowledge and records information without the customer's informed consent.
The Future of Privacy
The court considered it significant that cellphone tracking (unlike GPS) does not pinpoint an exact location, but only shows that the cellphone user is probably within a couple miles of a particular tower. The court also made clear that its opinion applied only to the gathering of historical data.
The court expressed no opinion as to whether a warrant would be required to track a cellphone location in real time. Tracking a cellphone while an individual is in his or her own home might require a warrant, as does receiving a transmission from a concealed beeper within the person's home. And while mobile phone users may "volunteer" to allow a cellphone provider to ping their cellphone, they do not expect cellphone providers, much less the government, to track their movements in real time.
Advances in technology often create challenges for courts as they balance privacy interests against the public's interest in arresting criminals. The dissent wondered, for instance, whether people lose their privacy interest in data from a Fitbit bracelet or a baby monitor when they voluntarily upload the data to a company's website. As technology continues to evolve, courts may need to adapt their understanding of the Fourth Amendment to protect individuals from electronic surveillance when the government cannot establish that the tracking will probably uncover evidence of a crime.