The Sixth Circuit Court of Appeals, last Tuesday, relying on the 1983 Supreme Court decision in U.S. v. Knotts, holding that the government's use of a beeper to track a suspect "amounted principally to the following of an automobile on public streets and highways," and distinguishing its current case from the 2012 Supreme Court ruling in U.S. v. Jones, which held that a government's placement of a GPS device on a car is a Fourth Amendment search, ruled that there is no Fourth Amendment violation when a criminal defendant is tracked through the GPS technology on his disposable mobile phone where the defendant "did not have a reasonable expectation of privacy in the data emanating from his cell phone that showed its location," according to a Law.com/National Law Journal article that morning.
Judge John Rogers, who wrote the opinion in U.S. v. Skinner, joined by Judge Eric Clay, with Judge Bernice Donald filing a separate opinion concurring in part and concurring in the judgment, reported that Skinner's case was different because there was no physical intrusion, the Law Journal said. "Because authorities tracked a known number that was voluntarily used while traveling on public thoroughfares, Skinner did not have a reasonable expectation of privacy in the GPS data and location of his cell phone. Therefore, suppression is not warranted and the district court correctly denied Skinner's motion to suppress."
"This is not a case in which the government secretly placed a tracking device in someone’s car," Rogers' ruling read. "The drug runners in this case used pay-as-you-go (and thus presumably more difficult to trace) cell phones to communicate during the cross-country shipment of drugs. Unfortunately for the drug runners, the phones were trackable in a way they may not have suspected. The Constitution, however, does not protect their erroneous expectations regarding the undetectability of their modern tools…. In short, Skinner did not have a reasonable expectation of privacy in the data emanating from his cell phone that showed its location."
Likewise, "Skinner's case also does not present the concern raised by Justice Alito's concurrence in Jones," the decision read. "There may be situations where police, using otherwise legal methods, so comprehensively track a person's activities that the very comprehensiveness of the tracking is unreasonable for Fourth Amendment purposes. As Justice Alito recognized, prior to certain advances in technology, 'practical' considerations often offered 'the greatest protections of privacy.' Id. at 963. For instance, in the situation presented in Jones, 'constant monitoring of the location of a vehicle for four weeks . . . would have required a large team of agents, multiple vehicles, and perhaps aerial assistance.' Id. Technology, however, has made it possible to conduct a level of extreme comprehensive tracking, 'secretly monitor[ing] and catalogu[ing] every single movement' that the defendant made over four weeks, that previously would have been impossible. Id. at 964. No such extreme comprehensive tracking is present in this case. Justice Alito's concurrence and the majority in Jones both recognized that there is little precedent for what constitutes a level of comprehensive tracking that would violate the Fourth Amendment. Id. at 954, 964. Skinner's case, however, comes nowhere near that line."
The University of Pittsburg's Jurist PaperChase also had a article.