At issue is interpretation of the Fourth Amendment, which defines illegal and unreasonable searches and seizures. In this case, prosecutors culled cell phone data to track Timothy Ivory Carpenter in his role behind multiple electronics store robberies in Michigan and Ohio. Carpenter and others were found guilty; the Supreme Court case is focusing on how prosecutors went after him.
All told, prosecutors used "127 days of records" obtained from cell phone companies. Those data points placed Carpenter in various locations, often very near to the reported robberies; the information, of course, also provided prosecutors with a detailed map of Carpenter's other daily activities, like where and when he attended church.
Because those records weren't obtained with a judicial search warrant showing probable cause in the case, the Supreme Court is being asked to determine whether prosecutors crossed a constitutional boundary — and whether American citizens may expect some degree of privacy in the use of their smartphones and other GPS-strapped electronics.
“Carpenter could be the most important electronic privacy case of the 21st century,” National Constitution Center President Jeffrey Rosen told the New York Times.
According to the U.S. Sixth Circuit Court of Appeals, "In April 2011, police arrested four men suspected of committing a string of armed robberies at Radio Shacks and T-Mobile stores in and around Detroit. One of the men confessed that the group had robbed nine different stores in Michigan and Ohio between December 2010 and March 2011, supported by a shifting ensemble of 15 other men who served as getaway drivers and lookouts." (The Ohio hit involved a Radio Shack in Warren on March 4, 2011.)
In 2014, Carpenter, the apparent ringleader, was sentenced to 116 years in federal prison.
While the Supreme Court will hear arguments beginning on Wednesday, a decision on the Carpenter matter isn't expected for months.
Stephen Sachs, a former Maryland attorney general, penned an insightful op-ed on this case, tracing the precedent set in an earlier telecom records criminal case (Smith v. Maryland). Sachs writes:
When the Supreme Court decided Smith, in the pre-dawn of the digital age, we didn’t know about the Internet, smartphones, cloud computing, Facebook or Twitter. No one involved in the case could foresee the digital revolution that was to come.
That new world is defined by the rapid increase in sophisticated — and invasive — technology. It is also defined by a relentless and pervasive assault on privacy. ...
The Supreme Court should develop a modern Fourth Amendment doctrine. Such a test would recognize the legitimate claims of law enforcement but set objective boundaries — such as the duration of an intrusion or the nature of the data seized — that constrain those claims. The Carpenter case is the court’s opportunity to do so.