RETHINKING REVERSE LOCATION SEARCH WARRANTS.

• Author: Rathi, Mohit

INTRODUCTION 807 I. REVERSE LOCATION SEARCH WARRANTS AND THE ROLE OF GOOGLE 808 A. How Reverse Location Search Warrants Work 808 B. Google's Cooperation with Law Enforcement 811 C. Google's Response to Privacy Concerns 813 II. REVERSE LOCATION SEARCH WARRANTS: CHALLENGES AND BENEFITS 815 A. Challenges Posed by Reverse Location Search Warrants 815 1. How Reverse Location Search Warrants Are Served to Judges 816 2. Concerns Related to Accuracy and Effectiveness 817 3. The Collection of Innocent People's Data 819 B. Societal Benefits Created by Reverse Location Search Warrants 820 1. Solving Crimes 820 III. POTENTIAL FOURTH AMENDMENT CHALLENGES TO REVERSE LOCATION SEARCH WARRANTS 823 A. Reverse Location Search Warrants as "General Warrants" 824 B. Location Information & Probable Cause 824 C. Probable Cause Analysis as Applied to Reverse Location Search Warrants 826 IV. PROPOSED JUDICIAL AND LEGISLATIVE SOLUTIONS 829 A. Alternative Frameworks: A New Probable Cause Exception 829 B. Legislative Solutions 831 1. Printed Maps Requirement 832 2. Mandated Anonymization Process for the First Warrant 833 3. Erasing Unnecessary Data Collected by Reverse Location Search Warrants 834 CONCLUSION 836 INTRODUCTION

From Orwell to The Hunger Games, the concept of a dystopian world where every citizen's actions are monitored and reported has been a part of our society's subconscious for the past few decades. There is a growing sense of fear among many people that the same technological changes that have drastically improved our lifespan and productivity might also bring about the end of privacy as we know it. (1) This Comment examines one such technological change being adopted by local and federal law enforcement agencies across the country: the reverse location search warrant. This type of warrant allows police officers to request cell phone location information from any mobile device within a certain radius of a crime scene at the time the crime occurred.

This powerful new technology has the potential to make our lives safer by helping law enforcement catch dangerous criminals, but it also provides law enforcement with unprecedented discretion in accessing private location information. As is so often the case with crime-solving technology, the question is not whether reverse location search warrants will become more common, but when they will. In light of this new technology, it is important to consider what can be done to protect fundamental privacy concerns.

More specifically, the reverse location search warrant has the potential to erode the Fourth Amendment protection from warrants that lack probable cause. Currently, courts use the probable cause framework when analyzing warrants, but reverse location search warrants present unique technological and constitutional issues that are more difficult to analyze under traditional probable cause analysis. Accordingly, this Comment argues that courts should move away from the probable cause framework, at least within the context of reverse location search warrants, to ensure that they can adequately protect fundamental privacy concerns. If courts are unwilling to do so, then federal and state legislatures should adopt new laws and regulations to ensure that reverse location search warrants are defined narrowly and that judges have adequate information when deciding whether to approve these warrants.

Part I of this Comment provides background information on reverse location search warrants and the process police officers use to request them. It also analyzes the role of Google, the primary provider of detailed location information in the modern landscape, in cooperating with law enforcement agencies. Part II outlines technical concerns raised by reverse location search warrants, especially with regards to the judicial approval process, and discusses the potential societal benefits of adopting reverse location search warrant technology. Part III discusses Fourth Amendment "probable cause" jurisprudence broadly, as well as the constitutional challenges reverse-location search warrants are likely to face in coming years. Part IV proposes creating an exception to Fourth Amendment probable cause jurisprudence in the context of reverse location search warrants, before finally suggesting three common-sense legislative proposals that could collectively limit these warrants' impact on privacy rights.

1. REVERSE LOCATION SEARCH WARRANTS AND THE ROLE OF GOOGLE

   The reverse location search warrant is a relatively new technology employed by police officers to catch criminals using the location information stored on criminals' phones. This Part of the Comment will provide background information on the reverse location search warrant, including a high-level description of the technology and how police officers use it. It will then describe the role of Google, the primary provider of location information for reverse location search warrants, in cooperating with law enforcement agencies across the country. Lastly, this Part will address Google's response to privacy concerns and its efforts to push back against overly broad requests from law enforcement.

   1. HOW REVERSE LOCATION SEARCH WARRANTS WORK

      Since at least 2017, law enforcement officers across the country have been using reverse location search warrants. (2) Rather than targeting a specific person, reverse location search warrants target location information pulled from mobile devices within a specified location. (3) This technology is gaining prominence partially due to the efforts of a corporation, ZetX, which travels around the country promoting its new software, Trax, to local law enforcement agencies. (4) Trax "recognizes cell phone data in any format from any provider and uses it to map the cell towers, create visuals of call information, [and] highlight callers' habits." (5) Once law enforcement installs this software, Trax can even automatically fill out search warrants: police officers simply select the area where the crime occurred on a map, and the longitudinal coordinates of the crime scene automatically populate directly into the warrant. (6) This technology, combined with corporations such as Google's extensive location tracking, makes it easier for law enforcement to request more reverse location search warrants.

      Reverse location search warrants are typically split into two or three smaller warrant requests. (7) In the first warrant, law enforcement requests location data from a company--almost always Google. (8) That company provides location information from the smartphone of everyone who has come within a set distance of the crime scene. (9) This information is anonymous at first. (10) Once law enforcement officers narrow down the list of potential suspects based on the individual movement patterns revealed by the initial data, they request a second warrant to acquire more details, including the names and account information of any suspects. (11) The way Google obtains this information depends on the type of phone a suspect uses. (12) Google obtains this information from Android phones directly; for other smartphones, Google obtains this information through its applications, such as Gmail, Chrome, or Google Maps. (13) Google derives location information from GPS tracking instead of cell-site location information (CSLI), which the Supreme Court has held requires a showing of probable cause to access. (14) GPS location tracking derives location information from mobile devices directly instead of triangulating their position based on cell phone towers; as such, it provides more accurate and detailed information than CSLI. (15)

      The collected GPS information is then loaded into Google's platform for hosting location data, Sensorvault, which Google also uses for targeted advertising. (16) For instance, Google uses Sensorvault to check if a person physically entered a store he or she viewed advertisements for online and then reports back to the store about whether the advertisement they purchased was effective. (17) It is possible to opt out of sharing location information with Google in this way; (18) however, Google prompts users to re-enable Sensorvault when setting up applications such as Google Maps or even regular Google searches with location enabled. (19) Thus, it is difficult for Google users to avoid having their location information collected.

      Law enforcement has employed the reverse location search warrant in multiple jurisdictions. (20) Police departments in Raleigh, North Carolina; Orange County, California; and Minnesota have all used this technology in the last two years. (21) The reverse location search warrant's growing use raises serious Fourth Amendment concerns, as people can be searched through the first warrant (22) simply because they walked near a crime scene, which may not satisfy traditional probable cause analysis. (23) As explained further infra, (24) the reverse location search warrant arguably puts the cart before the horse through this first smaller warrant. While the second warrant in a reverse location search warrant might satisfy the probable cause framework, the first warrant has a much weaker justification because it is granted simply on the basis of an individual being near a crime scene.

   2. GOOGLE'S COOPERATION WITH LAW ENFORCEMENT

      Google can lawfully provide law enforcement officials with customer location information through the third-party doctrine, a common law principle which states that people who voluntarily give up their information to third parties have "no reasonable expectation of privacy." (25) In the case of reverse location search warrants, the third party is typically Google, which receives up to 180 requests for location information from law enforcement per week. (26) Under this doctrine, by agreeing to use location services, customers would likely be considered to have given up their location information to Google. (27) Thus, consumers who opt into Google's...