Has Katz Become Quaint? Use Of Big Data To Outflank The Fourth Amendment

This article was prepared for Future of Privacy Forum and the Stanford Center for "Internet & Society's 'Big Data and Privacy: Making Ends Meet'" workshop.

Introduction

On December 14, 2010, a federal court, upon a government motion, entered an order pursuant to the Stored Communications Act (SCA) requiring Twitter to turn over to the government subscriber information concerning the accounts of three Twitter users. The order demanded only "non-content" data: names, addresses, and all records of user activity, including dates, times, and IP address data for all subscriber activity since November 1, 2009.

The subscribers filed a motion to vacate the order on grounds that it was insufficient under the SCA and violated both the First and Fourth Amendments. The motion was denied by the magistrate judge.1 The subscribers then filed objections to the magistrate judge's ruling.2 The district judge denied the subscribers' objections, agreeing with the magistrate judge that the subscribers lacked standing to challenge the SCA-based order on non-Constitutional grounds. The court also rejected the subscribers' Fourth Amendment challenge, stating that "any privacy concerns were the result of private action, not government action," and thus the "mere recording of . . . information by Twitter and subsequent access by the government cannot by itself violate the Fourth Amendment."3

The problems illustrated by this case are twofold. First, in the age of big data, the collection and analysis of "non-content" data can yield far more information about someone than was thought when the SCA was first drafted.4 Properly applied, big data analytics can make record data more illuminating to the analyst than content, heightening concerns over reduced SCA protections for non-content data. Second, since this data is collected by third party providers, the government can obtain this data without dealing with Fourth Amendment protections,5 possibly bypassing the courts altogether.6 Furthermore, the government's focus on national security since 2001 has resulted in an increase in requests for such data, some of which remain unexamined due to government claims of state secrecy.7 This essay argues that the nexus of ubiquitous computing and big data analytics has rendered existing standards of Fourth Amendment protection inadequate, and calls for a reexamination of these doctrines based on today's technologies.

Mosaic Theory and the Age of Big Data

In recent years, data storage capacities have increased by orders of magnitude, while associated costs have plummeted. Processing speeds have increased to the point that most people carry smartphones that are far more capable than the computers that sat on their desks a few years ago. These factors have combined to enable real time analysis of massive quantities of data, spurring research advances in fields as diverse as atmospheric science, genomics, logistics, and disease prevention.

These capabilities have not gone unnoticed by governments, which have employed big data analytics to reach previously unheard of dimensions of intelligence analysis.8 These techniques have spilled over into...