The Government’s obtaining of cell phone-site information from third-party service provides is a “search” under the Fourth Amendment, and requires a warrant based on probable cause, the U.S. Supreme Court held June 22 in Carpenter v. U.S..
Prosecutors suspected Timothy Carpenter of being involved in several robberies.
The Government applied for and received court orders under the Stored Communications Act for his cell phone records.  The Stored Communications Act allows a judge to compel telecom providers to provide records when the Government “offers specific and articulable facts showing that there are reasonable grounds to believe” that the records sought will be “relevant and material to an ongoing criminal investigation.”
The records were used to determine Carpenter’s locations was for at least a week.    
Carpenter moved to suppress the cell-site data on grounds that it was obtained without a warrant supported by probable cause.  The trial court denied the motion.
At trial, an FBI agent testified that the cell-site data placed Carpenter “right where” the robberies were “at the exact time.”
The Sixth Circuit affirmed the denial of the suppression motion on grounds that Carpenter lacked a reasonable expectation of privacy in cell-site data because he had shared it with the telecom service providers.
The Supreme Court reversed in a 5-4 opinion.
“[A] central aim of the Framers was to place obstacles in the way of a too permeating police surveillance,” Chief Justice Roberts wrote for the Court.  “We have kept this attention to Founding-era understandings in mind when applying the Fourth Amendment to innovations in surveillance tools.” 
The Court, for example, has required warrants for conducting thermo-imaging of people’s houses and searching their cellphones.  And the Court has recognized “a person’s expectation of privacy in his physical location and movements” by requiring a warrant for placing a GPS device on people’s cars.
The Court acknowledged that other decisions “draw a line between what person keeps to himself and what he shares with others,” but this third-party doctrine has been limited largely to relatively limited information such as bank records and pen registrars. 
Cell-site records are “qualitatively different” than bank records or telephone numbers dialed, the Court said.  “Much like GPS tracking of a vehicle, cellphone location information is detailed, encyclopedic, and effortlessly compiled.”
Prior to the technology age, society had an expectation that law enforcement agents would not – and, as a practical matter, could not – catalogue their every movement for an extended period of time.  But cell phone information changes that, and allows the Government to discover through a person’s movements their familial, political, professional, religious and sexual associations.
“These location records hold for many Americans the privacies of life,” the Court said.
“Given the unique nature of cell phone location records, the fact that the information is held by a third party does not by itself overcome the user’s claim to Fourth Amendment protection,” the Court said.  “[W]e hold that an individual maintains a legitimate expectation of privacy in the record of his physical movements as captured” through cell phone location data.  “[W]e also conclude that the Government must generally obtain a warrant supported by probable cause before acquiring such records.”
Here, the Government’s acquisition of Carpenter’s records by showing that there were “reasonable grounds” for believing the records were “relevant and material to an ongoing investigation” “falls well short of the probable cause required for a warrant,” the Court said.  There must usually be “some quantum of individualized suspicion before a search or seizure can take place.”
The Court emphasized that the Government can still use subpoenas to obtain records in the “overwhelming” majority of investigations.  “We hold only that a warrant is required in the rare case where the suspect has a legitimate privacy interest in the records held by a third party.”
Lastly, the Court said that there may be circumstances where a warrant is not required, such as exigent circumstances.  “Such exigencies include the need to pursue a fleeing suspect, protect individuals who are threatened with imminent harm, or prevent the imminent destruction of evidence.”
Justices Kennedy, Thomas, Alito and Gorsuch each wrote dissenting opinions.
Kennedy said that cell-site records “are no different from many other kinds of business records the Government has a lawful right to obtain by compulsory process.  Customers like [Carpenter] do not own, possess, control, or use the records, and for that reason have no reasonable expectation that they cannot be disclosed pursuant to lawful compulsory process.”
“This case should be resolved by interpreting accepted property principles as the baseline for reasonable expectation of privacy,” he said.
“Here the only question necessary to decide is whether the Government searched anything of Carpenter’s when it used compulsory process to obtain cell-site records from Carpenter’s cell phone service providers,” he said.  The answer is “no.”
Thomas agreed that the case should turn on “on whose property was searched,” but further urged the Court to abandon Katz’s “reasonable expectation of privacy test” altogether. 
“The Katz test has no basis in the text or history of the Fourth Amendment,” he said.  “Until we confront the problems with this test, Katz will continue to distort Fourth Amendment jurisprudence.”
Alito said the Court’s opinion was “revolutionary” in “treating an order to produce like an actual search,” and in allowing “a defendant to object to the search of a third party’s property.” 
He said the opinion will cause “upheaval” and “destabilizes long-established Fourth Amendment doctrine.”
 “Must every grand jury subpoena duces tecum be supported by probable cause?” he said.
Gorsuch advises litigants to raise issues
Perhaps the most interesting and useful dissent was Gorsuch’s.  He said neither the “reasonable expectation of privacy test” nor the notion that people waive all privacy just because they entrust information to third parties work. 
“Can the government demand a copy of all your e-mails from Google or Microsoft without implicating your Fourth Amendment rights?  Can it secure your DNA from 23andMe without a warrant and probable cause?” Gorsuch asked as examples.  “[T]hat result strikes most lawyers and judges today – me included – as pretty unlikely,” and shows that the third-party doctrine is “not only wrong, but horribly wrong.”
“People often do reasonably expect that information they entrust to third parties … will be kept private,” he said.
But the “reasonable expectation of privacy test” has often led to “unpredictable” results, he said.  For example, the Court has held that there is no expectation of privacy in a helicopter hovering 400 feet over a person’s property – “Try that one on your neighbors” — or expectation of privacy in garbage by a curb – “I … doubt that most people spotting a neighbor rummaging through their garbage would think they lacked reasonable grounds to confront the rummager.”
He urged the Court to return to its original understanding of the Fourth Amendment, which requires a person to show that the searched property was “yours under the law” but also understanding that “the fact that a third party has access to or possession of your papers and effects does not necessarily eliminate your interest in them.” 
He noted that the Court, in 1877, had held that the Government cannot search a letter a person gives to the Post Office for mailing.  This “suggests the existence of a constitutional floor below which Fourth Amendment rights may not descend.” 
“Ever hand a private document to a friend to be returned?  Toss your keys to a valet at a restaurant?  Ask your neighbor to look after your dog while you travel?” he said.  “You would not expect the friend to share the document with others; the valet to lend your car to his buddy; or the neighbor to put Fido up for adoption.  Entrusting your stuff to others is a bailment.”
“[F]ew doubt that e-mail should be treated much like the traditional mail it has largely supplanted – as a bailment in which the owner retains a vital and protected legal interest,” he said.
But “complete ownership or exclusive control of the property” is not “always a necessary condition to the assertion of a Fourth Amendment right,” he said.  For example, renters of a home owned by others have Fourth Amendment rights. 
He said that legislation may define privacy or property rights regarding data stored by third parties.  He conceded that even in Carpenter’s case, “[i]t seems to me entirely possible a person’s cell-site data could qualify as his papers or effects under existing law,” since various statutes may create such an interest.
“The problem is that we do not know anything more,” Gorsuch said.  “Mr. Carpenter pursued only a Katz ‘reasonable expectations’ argument.  He did not invoke the law of property or any analogies to the common law….In these circumstances, I cannot help but conclude – reluctantly – that Mr. Carpenter forfeited perhaps his most promising line of argument.”
He urged litigants not to forfeit Fourth Amendment arguments based on property rights, legislation and common law. 
“Litigants have had fair notice since at least United States v. Jones (2012)[placing GPS device on car was a search] and Florida v. Jardines (2013)[drug-dog sniff on a porch was a trespass] that arguments like these may vindicate Fourth Amendment interests even where Katz arguments do not.  Yet the arguments have been unmade, leaving courts to the usual Katz hand-waving.”