A Technology-Centered Approach to Quantitative Privacy
Social Science Research Network
We are at the cusp of a historic shift in our conceptions of the Fourth Amendment driven by dramatic advances in technologies that continuously track and aggregate information about our daily activities. The Fourth Amendment tipping point was marked this term by United States v. Jones. There, law enforcement officers used a GPS device attached to Jones's car to follow his movements for four weeks. Although Jones was resolved on narrow grounds, five justices signed concurring opinions defending
... opinions defending a revolutionary proposition: that citizens have Fourth Amendment interests in substantial quantities of information about their public or shared activities, even if they lack a reasonable expectation of privacy in each of the constitutive particulars. This quantitative approach to the Fourth Amendment has since been the focus of considerable debate. Among the most compelling challenges are identifying its Fourth Amendment pedigree, describing a workable test for deciding how much information is enough to trigger Fourth Amendment interests, and explaining the doctrinal consequences. This Article takes up these challenges. Our analysis and proposal draw upon insights from information privacy law. Although information privacy law and Fourth Amendment jurisprudence share a fundamental interest in protecting privacy interests, these conversations have been treated as theoretically and practically discrete. This Article ends that isolation and the mutual exceptionalism that it implies. As information privacy scholarship suggests, technology can permit government to know us in unprecedented and totalizing ways at great cost to personal development and democratic institutions. We argue that these concerns about panoptic surveillance lie at the heart of the Fourth Amendment as well. We therefore propose a technology-centered approach to measuring and protecting Fourth Amendment interests in quantitative privacy. As opposed to proposals for case-by-case assessments of information "mosaics," which have so far dominated the debate, we argue that government access to technologies capable of facilitating broad programs of continuous and indiscriminate monitoring should be subject to the same Fourth Amendment limitations applied to physical searches.