An ongoing court case involving the armed theft of phones from RadioShack and T-Mobile could set a legal precedent determining what protections the Fourth Amendment of the U.S. Constitution provides a user's digital information. The Supreme Court case is filed as Carpenter v. United States and centers around whether or not Timothy Carpenter had any reasonable expectation of privacy regarding his location data. A court order had been granted in lieu of a warrant in order to provide law enforcement with access to that data, following Carpenter's involvement in the above-mentioned crime. While it isn't an unusual method for obtaining the data, privacy advocates and Carpenter's representatives argue that the broad collection of consumer location information puts the general public at risk. From that perspective, the police and others in positions of authority could easily track the physical movement of any citizen regardless of whether there is probable cause. Moreover, it's argued the collection of that data from many technology-based companies doesn't allow the user any choice in the matter.
However, at least two prior cases had already determined that any sharing of information by a person with third-parties typically invalidates reasonable expectation of privacy. Often referred to as the "third-party doctrine," that effectively nullifies Fourth Amendment protections of any personal information sold or given to a company. The third party, in this case, is Carpenter's mobile carrier. In short, Carpenter's agreement to share his location data with his provider, an agreement put in place simply by signing up for cellphone service. Because cell phones track location on users hundreds of times per day as part of their operation and carriers are a third-party, law enforcement was well within the Amendment's legal bounds.
Legal experts, meanwhile, appear to be torn on the matter and the American Civil Liberties Union has taken up the case in Carpenter's defense. A significant portion of concern stems from the fact that surveillance was ongoing for approximately seven months. Others have pointed out that the third-party doctrine is not well-written and doesn't fit well with the digital age since so much personal information swaps hands with third-parties on a regular basis. The issue has been likened to a landlord who allows police to enter and search a property currently rented to a tenant without probable cause. Those in favor of the court's stance, on the other hand, say that reasonable expectation of privacy is negated by the fact that everybody knows their location is being tracked by carriers.