Last month, a Sixth Circuit panel held in United States v. Skinner that repeatedly pinging a cell phone in order to obtain its GPS coordinates was not a Fourth Amendment search. This week, the ACLU, CDT, EFF, and EPIC filed an amicus brief asking the Sixth Circuit to reconsider the case en banc.
Greg Nojeim, senior counsel for the Center for Democracy & Technology, wrote on CDT's blog that the panel decision was based on a misunderstanding
that cell phones normally "give off" GPS location information. Instead, mobile providers have to take a special step -- sending a signal to the phone to direct it to produce the GPS data. Unless they take that step, there is no location data at the provider for the government to seize. As a result, the court should not have analyzed the case under the third party records doctrine, which says a person has no Fourth Amendment interest in information shared with a third party.The groups suggest that the Supreme Court's decision in Jones conflicts with Skinner insofar as Sotomayor and Alito's concurring opinions can be read together to provide Fourth Amendment protection even when tracking does not involve a trespass.
Neither concurring opinion set a firm guideline as to when an act of surveillance will be unreasonable under the Fourth Amendment, and this amicus brief suggests that Skinner's "three days of cell phone tracking should be considered 'prolonged.'" Jones's surveillance by GPS was for 28 days, clearly a prolonged search according to Alito.