On Tuesday, the Supreme Judicial Court ruled in Commonwealth v. Augustine that the Massachusetts constitution prohibits law enforcement officials from gathering cellphone records that track individuals’ locations without first obtaining a search warrant from a state judge. Harvard Law School’s Cyberlaw Clinic, which provides pro-bono legal services to clients in matters involving the Internet, technology and intellectual property, filed a friend-of-the-court brief in this case on behalf of the Electronic Frontier Foundation. The brief argued against warrantless collection of people’s location records. The SJC decision agreed that location data is sufficiently sensitive to require constitutional protection. The ruling built on the court’s decision last year in Commonwealth v. Rousseau requiring warrants for GPS tracking, another case in which the HLS Cyberlaw Clinic submitted an amicus brief.

Commonwealth v. Augustine stems from the 2004 murder of Malden woman, Julaine Jules. Suspecting her former boyfriend, Shabazz Augustine, investigators obtained his cellphone records from his wireless carrier in an attempt to determine where he had been at the time of the killing. Investigators were able to get his phone records based on the 1986 Stored Communications Act that allows police to obtain such information by convincing a judge that it may be relevant to an investigation, but without obtaining a search warrant. Augustine’s attorney convinced a judge that the cell site location evidence was obtained illegally, and the judge suppressed the evidence gleaned from the cell phone service provider. But the Commonwealth appealed.

In a blog post on February 19th by Kit Walsh, clinical instructional fellow at the HLS Cyberlaw Clinic, Walsh states that cellphone users should not be subject to warrantless collection of location records simply by the act of making a phone call: “Significantly, the court also rejected the Commonwealth’s argument that cell phone users surrender any privacy interest in their location records merely by permitting cell phone providers to create those records about them. The court noted that a user making a phone call is not consciously conveying their location information to a provider and declined to extend the privacy exception known as the ‘third party doctrine’ in a way that would open this location data to warrantless snooping by the police.”

Matthew Segal, legal director of the American Civil Liberties Union of Massachusetts, called the ruling “an enormous victory for everybody in Massachusetts who cares about privacy. It protects people in Massachusetts and gives them rights that Massachusetts law enforcement officers have to respect,” Segal said in a Boston Globe article by Hiawatha Bray on the ruling.

“We at the Clinic are pleased that the SJC has invited the public to brief its digital civil liberties cases and to help them think through the application of long-established rights to new technologies,” Walsh wrote in his blog post. “And we’re especially pleased that the SJC has defended the continued vitality of those rights in both of the privacy cases we’ve briefed before them.”