Source: http://socket.newrepublic.com/article/149328/supreme-court-cares-digital-privacy
Timestamp: 2019-04-20 22:47:51+00:00

Document:
The Supreme Court handed down a major decision on digital privacy on Friday, ruling in Carpenter v. United States that Fourth Amendment protections from “unreasonable searches and seizure” apply to cell-phone location data. In short, police need a warrant to electronically retrace a cell phone owner’s steps in a criminal investigation.
Friday’s ruling extends what has become a theme for the Roberts Court: ensuring that Americans’ privacy rights keep pace with technological advances. In the past six years, the justices have also ruled that cops need a judge’s permission to attach GPS tracking devices to suspects’ cars and to search a person’s cell phone during an arrest. Friday’s decision continued the court’s trend.
For most of American history, there were practical limits on the government’s ability to systematically invade its citizens’ privacy. Tracking the movements of every person at all times in the nineteenth and early twentieth centuries would have required feats of manpower and bureaucracy beyond all but the most despotic regimes’ dreams. Modern technology, for all its benefits, has also changed that calculus by making vast quantities of personal information available at a moment’s notice.
Friday’s ruling is also good news for Timothy Carpenter, the case’s titular namesake. He was one of four men convicted by a federal jury in 2011 for participating in a series of robberies targeting electronic stores in Michigan and Ohio. To prove that Carpenter was at the scenes of the crimes, federal investigators sought what’s known as historical cell-site location information (CSLI), from Carpenter’s cell phone.
What is historical CSLI? As part of their everyday functions, cell phones regularly transmit data to nearby cell towers, like submarines using sonar to navigate the ocean depths. In denser urban areas, a cell phone will ping multiple towers at the same time, making it possible to triangulate the source with increasing precision. Each cell tower records those pings and who sent them, storing the information in databases maintained by each telecommunications company.
With enough data from enough towers, anyone with access to the database could stitch together a comprehensive account of when and where each cell phone has been. At least 95 percent of Americans have personal cell phones, many of whom rarely step away more than a few feet from them. As a result, tracing where a cell phone has been is no different from tracking where a person has been. The privacy implications are inescapable.
Investigators ultimately obtained 127 days of cell-site records from two different mobile providers, which yielded 12,898 location points that revealed Carpenter’s movements. A federal agent testified that those points placed him near four of the robbery locations during the robberies in question. A jury found him guilty on multiple robbery and firearm-related charges and sentenced him to more than 100 years behind bars.
Carpenter asked lower courts to throw out the evidence on Fourth Amendment grounds. But they declined, citing two Supreme Court precedents dating back almost four decades. In the 1976 case United States v. Miller, the court upheld a whiskey bootlegger’s conviction after prosecutors obtained his bank records without a warrant. Three years later in Smith v. Maryland, the court signed off on the warrantless use of a pen register, a device that recorded which phone numbers were dialed on a particular telephone line.
Taken together, Miller and Smith established what’s known as the third-party doctrine. The Supreme Court often uses a “reasonable expectation of privacy” test to determine whether a police method counts as a Fourth Amendment “search,” and therefore whether a warrant is needed. Under the third-party doctrine, Americans lose a reasonable expectation of privacy if their personal information is stored by a third party, as with the bank records in Miller; or made readily available to a third party, as with Smith and the telephone company.
Applying that doctrine to modern technology, which is far more pervasive and ubiquitous than it was when Smith and Miller were decided in the 1970s, is an uneasy proposition. In 2012, the justices ruled in United States v. Jones that federal agents had violated the Fourth Amendment when they attached a GPS device to a car without a warrant. Justice Sonia Sotomayor wrote a concurring opinion in which she called on the court to revisit the third-party doctrine in light of technological advances.
Monday’s ruling in Carpenter began to move the court in that direction. It explicitly carves out an exception of sorts from the third-party doctrine for historical CSLI, citing its unusually intrusive nature. “After all, when Smith was decided in 1979, few could have imagined a society in which a phone goes wherever its owner goes, conveying to the wireless carrier not just dialed digits, but a detailed and comprehensive record of the person’s movements,” Roberts wrote.
In 2014, the justices again took technological changes into account in Riley v. California. Generally speaking, the courts have found that the Fourth Amendment doesn’t stop police from searching suspects during an arrest, citing the need to secure evidence and ensure officer safety. But the court drew a line when it came to searching a suspect’s cell phone under that exception. The immense amounts of personal data on a phone placed it beyond the exception’s scope. “The fact that technology now allows an individual to carry such information in his hand does not make the information any less worthy of the protection for which the Founders fought,” Roberts wrote for a unanimous court.
Previous generations of Supreme Court justices were often too willing to bend the Fourth Amendment when new technologies made it possible. In the 1928 case Olmstead v. United States, the Supreme Court ruled that wiretapping didn’t require a warrant at a time when telephone technology was still relatively new. It took 39 years for the court to reverse course. Roberts and his colleagues have made clear that they’re not eager to make the same mistakes again.

References: v. 
 v. 
 v. 
 v. 
 v. 
 v.