The Cyberlaw Clinic filed an amicus brief (PDF) this week in the Supreme Judicial Court of Massachusetts on behalf of the American Civil Liberties Union of Massachusetts (ACLUM) and the Electronic Frontier Foundation (EFF) in Commonwealth v. Estabrook, SJC–11833. The case concerns location privacy and cell phone technology — specifically, whether law enforcement can gather a large amount of cell phone location information if it only plans to use a small fraction of that information in a prosecution. This is the third brief the Clinic has filed on location privacy issues in Massachusetts, including briefs for EFF in Commonwealth v. Augustine and Commonwealth v. Rousseau in 2013.
Cellular service providers must know where their subscribers are at any given time to provide them with service. Providers therefore collect vast quantities of location information, tracking the movements of customers wherever they go. Last year, in Augustine, 467 Mass. 230 (2014), the Supreme Judicial Court ruled that, in general, the police must get a search warrant to obtain location information from a cellular service provider. The ruling left open the possibility, however, that the police might be able to obtain a “brief period” of location information without a warrant but, instead, with a court order that is considerably easier to obtain.
This latest brief argues that Augustine requires police to get a warrant to obtain location information even if they only plan to use a small amount. It urges the SJC to establish a blanket warrant requirement that applies whenever police seek cellphone location data. As the brief notes, considering the growing volume and accuracy of such data, and the confusion that the Augustine exception has created in the lower courts, a blanket warrant requirement would provide much-needed clarity to police, prosecutors, and the public. Such a rule would align Massachusetts with the dozen other states that have imposed blanket warrant requirements for cellphone location data, without any apparent ill effects on the ability of the police to investigate crimes.
The case is scheduled for argument on Thursday, May 7th, at the John Adams Courthouse in Boston. Special thanks go to HLS Cyberlaw Clinic students Abigail Colella (’16), Sandra Hanian (’15), and Travis West (’16), who worked closely with Vivek Krishnamurthy, Andy Sellars, and the amici, to prepare and file the brief.