Fourth Amendment

Would Autonomous Vehicles (AVs) Interfere with Our Fourth Amendment Rights?

May 10, 2022
Autonomous Vehicles, Constitutional Law, Data, Data Privacy, Fourth Amendment

Thao Nguyen, MJLST Staffer

Traffic accidents are a major issue in the U.S. and around the world. Although car safety features are continuously enhanced and improved, traffic crashes continue to be the leading cause of non-natural death for U.S. citizens. Most of the time, the primary causes are human errors rather than instrumental failures. Therefore, autonomous vehicles (“AVs”), which promise to be the automobiles that operate themselves without the human driver, are an exciting up and coming technology, studied and developed in both academia and industry[1].

To drive themselves, AVs must be able to perform two key tasks: sensing the surrounding environment and “driving”—essentially replacing the eyes and hands of the human driver.[2] The standard AV design today includes a sensing system that collects information from the outside world, assisting the “driving” function. The sensing system is composed of a variety of sensors,[3] most commonly a Light Detection and Ranging (LiDAR) and cameras.[4] A LiDAR is a device that emits laser pulses and uses sound navigation and ranging (“SONAR”) principles to get a depth estimation of the surroundings: the emitted laser pulses travel forward, hit an object, then bounce back to the receivers; the time taken for the pulses to travel back is measured, and the distance is computed. With this information about distance and depth, a 3D point cloud map is generated about the surrounding environment. In addition to precise 3D coordinates, most LiDAR systems also record “intensity.” “Intensity” is the measure of the return strength of the laser pulse, which is based, in part, on the reflectivity of the surface struck by the laser pulse. LiDAR “intensity” data thus reveal helpful information about the surface characteristics of their surroundings. The two sensors, the camera and the LiDAR, complement each other: the former conveys rich appearance data with more details on the objects, whereas the latter is able to capture 3D measurements[5]. Fusing the information acquired by each allows the sensing system to gain a reliable environmental perception.[6]

LiDAR sensing technology is usually combined with artificial intelligence, as its goal is to imitate and eventually replace human perception in driving. Today, the majority of artificial intelligences use “machine learning,” a method that gives computers the ability to learn without explicitly being programmed. With machine learning, computers train itself to do new tasks in a similar manner as do humans: by exploring data, identifying patterns, and improving upon past experiences. Applied machine learning is data-driven: the greater the breadth and depth of the data supplied to the computer, the greater the variety and complexity of the tasks that the computer can program itself to do. Since “driving” is a combination of multiple high-complexity tasks, such as object detection, path planning, localization, lane detection, etc., an AV that drives itself requires voluminous data in order to operate properly and effectively.

“Big data” is already considered a valuable commodity in the modern world. In the case of AVs, however, this data will be of public streets and road users, and the large-scale collection of this data is empowered further by various technologies to detect and identify, track and trace, mine and profile data. When profiles about a person’s traffic movements and behaviors exist in a database somewhere, there is a great temptation for the information to be used for other purposes than the purpose for which they were originally collected, as has been the case with a lot of other “big data” today. Law enforcement officers who get their hands on these AVs data can track and monitor people’s whereabouts, pinpointing individuals whose trajectories touch on suspicious locations at a high frequency. The trajectories can be matched with the individual identified via use of car models and license plates. The police may then identify crime suspects based on being able to see the trajectories of everyone in the same town, rather than taking the trouble to identify and physically track each suspect. Can this use of data by law enforcement be sufficiently justified?

As we know, use of “helpful” police tools may be restricted by the Fourth Amendment, and for good reasons. Although surveillance helps police officers detect criminals,[7] extraneous surveillance has its social costs: restricted privacy and a sense of being “watched” by the government inhibits citizens’ productivity, creativity, spontaneity, and causes other psychological effects.[8] Case law has given us guidance to interpret and apply the Fourth Amendment standards of “trespass” or “unreasonable searches and seizures” by the police. Three principal cases, Olmstead v. United States, 277 U.S. 438 (1928), Goldman v. United States, 316 U.S. 129 (1942), and United States v. Jones, 565 U.S. 400 (2012), a modern case, limit Fourth Amendment protection to protecting against physical intrusion into private homes and properties. Such protection would not be helpful in the case of LiDAR, which operates on public street as a remote sensing technology. Nonetheless, despite the Jones case, the more broad “reasonable expectation of privacy” test established by Katz v. United States, 389 U.S. 347 (1967) is more widely accepted. Instead of tracing physical boundaries of “persons, houses, papers, and effects,” the Katz test focuses on whether there is an expectation of privacy that is socially recognized as “reasonable.” The Fourth Amendment “protects people, not places,” wrote the Katz court.[9]

United States v. Knotts, 460 U.S. 276 (1983) was a public street surveillance case that invoked the Katz test. In Knotts, the police installed a beeper on to the defendant’s vehicle to track it. The Court found that such tracking on public streets was not prohibited by the Fourth Amendment: “A person traveling in an automobile on public thoroughfares has no reasonable expectation of privacy in his movements from one place to another.”[10] The Knotts Court thus applied the Katz test and considered the question of whether there was a “reasonable expectation of privacy,” meaning that such expectation was recognized as “reasonable” by society.[11] The Court’s answer is in the negative: unlike a person in his dwelling place, a person who is traveling on public streets “voluntarily conveyed to anyone who wanted to look at the fact that he was traveling over particular roads in a particular direction.”[12]

United States v. Maynard, 615 F.3d 544 (2010), another public street surveillance case taking place in the twenty-first century, reconsidered the Knotts holding regarding “reasonable expectation of privacy” on public streets. The Maynard defendant argued that the district court erred in admitting evidence acquired by the police’s warrantless use of a Global Pointing System (GPS) device to track defendant’s movements continuously for a month.[13] The Government invoked United States v. Knotts and its holding that “[a] person traveling in an automobile on public thoroughfares has no reasonable expectation of privacy in his movements from one place to another.”[14] The DC Circuit Court of Appeals, however, distinguished Knotts, pointing out that the Government in Knotts used a beeper that tracked a single journey, whereas the Government’s GPS monitoring in Maynard was sustained 24 hours a day continuously for one month.[15]The use of the GPS device over the course of one month did more than simply tracking defendant’s “movements from one place to another.” The result in Maynard was the discovery of the “totality and pattern” of defendant’s movement. [16]The Court is willing to make a distinction between “one path” and “the totality of one’s movement”: since someone’s “totality of movement” is much less exposed to the view of the public and much more revealing of that person’s personal life, it is constitutional for the police to track an individual on “one path,” but not that same individual’s “totality of movement.”

Thus, with time the Supreme Court appears to be recognizing that when it comes to modern surveillance technology, the sheer quantity and the revealing nature of data collected on movements of public street users ought to raise concerns. The straightforward application of these to AV sensing data would be that data concerning a person’s “one path” can be obtained and used, but not the totality of a person’s movement. It is unclear where to draw the line      between “one path” and “the totality of movement.” The surveillance in Knotts was intermittent over the course of three days,[17] whereas the defendant in Maynard was tracked for over one month. The limit would perhaps fall somewhere in between.

Furthermore, this straightforward application is complicated by the fact that the sensors utilized by AVs do not pick up mere locational information. As discussed above, AV sensing system, being composed of multiple sensors, capture both camera images and information about speed, texture, and depth of the object. In other words, AVs do not merely track a vehicle’s location like a beeper or GPS, but they “see” the vehicle through their cameras and LiDAR and radar devices, gaining a wealth of information. This means that even if only data about “one path” of a person movement is extracted, this “one path” data as processed by AV sensing systems is much more in-depth than what a beeper or CSLI can communicate. Adding to this, current developers are proposing to create AVs networks that share data among many vehicles, so that data on “one path” can potentially be combined with other data of the same vehicle’s movement, or multiple views of the same “one path” from different perspectives can be combined. The extensiveness of these data goes far beyond the precedents in Knotts and Maynard. Thus, it is foreseeable that unwarranted subpoenaing AVs sensing data is firmly within the Supreme Court’s definition of a “trespass.”

[1] Tri Nguyen, Fusing LIDAR sensor and RGB camera for object detection in autonomous vehicle with fuzzy logic approach, 2021 International Conference on Information Networking (ICOIN) 788, 788 (2021).

[2] Id. (“An autonomous vehicle or self-driving car is a vehicle having the ability to sense the surrounding environment and capable of operation on its own without any human interference. The key to the perception system holding responsibility to collect the information in the outside world and determine the safety of the vehicle is a variety of sensors mounting on it.”)

[3] Id. “The key to the perception system holding responsibility to collect the information in the outside world and determine the safety of the vehicle is a variety of sensors mounted on it.”

[4] Heng Wang and Xiaodong Zhang, Real-time vehicle detection and tracking using 3D LiDAR, Asian Journal of Control 1, 1 (“Light Detection and Ranging (LiDAR) and cameras [6,8] are two kinds of commonly used sensors for obstacle detection.”)

[5] Id. (“Light Detection and Ranging (LiDAR) and cameras [6,8] are two kinds of commonly used sensors for obstacle detection.”) (“Conversely, LiDARs are able to produce 3D measurements and are not affected by the illumination of the environment [9,10].”).

[6] Nguyen, supra note 1, at 788 (“Due to the complementary of two sensors, it is necessary  to gain a more reliable environment perception by fusing the  information acquired from these two sensors.”).

[7] Raymond P. Siljander & Darin D. Fredrickson, Fundamentals of Physical Surveillance: A Guide for Uniformed and Plainclothes Personnel, Second Edition (2002) (abstract).

[8] Tamara Dinev et al., Internet Privacy Concerns and Beliefs About Government Surveillance – An Empirical Investigation, 17 Journal of Strategic Information Systems 214, 221 (2008) (“Surveillance has social costs (Rosen, 2000) and inhibiting effects on spontaneity, creativity, productivity, and other psychological effects.”).

[9] Katz v. United States, 389 U.S. 347, 351 (1967).

[10] United States v. Knotts, , 460 U.S. 276, 281 (1983) (“A person traveling in an automobile on public thoroughfares has no reasonable expectation of privacy in his movements from one place to another.”)

[11] Id. at 282.

[12] Id.

[13] United States v. Maynard, 615 F.3d 544, 549 (2010).

[14]  Id. at 557.

[15] Id. at 556.

[16] Id. at 558 “[O]nes’s movements 24 hours a day for 28 days as he moved among scores of places, thereby discovering the totality and pattern of his movements.”).

[17] Knotts at 276.

Inconceivable! How the Fourth Amendment Failed the Dread Pirate Roberts in United States v. Ulbricht

November 21, 2020
Constitutional Law, Cyber Security, Fourth Amendment, Law Enforecement

Emily Moss, MJLST Staffer

It is not an overstatement to claim that electronic devices, such as laptop and smart phones, have “altered the way we live.” As Chief Justice Roberts stated, “modern cell phones . . . are now such a pervasive and insistent part of daily life that the proverbial visitor from Mars might conclude they were an important feature of human anatomy.” Riley v. California, 573 U.S. 373, 385 (2014). These devices create new digital records of our everyday lives. United States v. Ulbricht, 858 F.3d 71 (2d Cir. 2017) is one of many cases that grapple with when the government should gain access to these records.

In February 2015, a jury found Ross William Ulbricht (aka “Dread Pirate Roberts” or “DPR”) guilty on seven counts related to his creation and operation of Silk Road. United States v. Ulbricht, 858 F.3d 71, 82 (2d Cir. 2017). Silk Road was an online criminal marketplace where, using the anonymous currency Bitcoin, “users principally bought and sold drugs, false identification documents, and computer hacking software.” Id. Government trial evidence showed that, hoping to protect Silk Road anonymity, DPR commissioned the murders of five people. Id. at 88. However, there is no evidence that the murders actually transpired. Id.

On appeal, the Second Circuit upheld both the conviction and Ulbricht’s two-life sentence. Ulbricht, 858 F.3d at 82. Ulbricht argued, inter alia, that “the warrant[] authorizing the government to search his laptop . . . violated the Fourth Amendment’s particularity requirement.” Id. at 95. The warrant authorized “opening or ‘cursorily reading the first few’ pages of files to ‘determine their precise contents,’ searching for deliberately hidden files, using ‘key word searches through all electronic storage areas,’ and reviewing file ‘directories’ to determine what was relevant.” Id. at 101–02. Ulbricht claimed that the warrant violated the Fourth Amendment’s particularity requirement because it “failed to specify the search terms and protocols” that the government was required to employ while searching Ulbricht’s laptop. Id. at 102.

The court acknowledged that particularity is especially important when the warrant authorizes the search of electronic data, as the search of a computer can expose “a vast trove of personal information” including “sensitive records.” Id. at 99. It noted that “a general search of electronic data is an especially potent threat to privacy because hard drives and e-mail accounts may be ‘akin to a residence in terms of the scope and quantity of private information [they] may contain’ . . . Because of the nature of digital storage, it is not always feasible to ‘extract and segregate responsive data from non-responsive data,’. . . creating a ‘serious risk that every warrant for electronic information will become, in effect, a general warrant.’” Id. (internal citations omitted).

Nonetheless, the court rejected Ulbricht’s claim that the laptop warrant failed to meet the Fourth Amendment’s particularity requirement. It reasoned that it would be impossible to identify how relevant files would be named before the laptop search began, which the government reasonably anticipated when requesting the laptop warrant. Id. at 102 (emphasizing examples where relevant files and folders had misleading names such as “aliaces” or “mbsobzvkhwx4hmjt”). Further, the court held that broad search protocols were appropriate given that the alleged crime involved sophisticated technology and masking identity. Id. Ultimately, the court emphasized that the “fundamental flaw” in Ulbricht’s argument was that it equated a broad warrant with a violation of the particularity requirement. Id. Using the analogy of searching an entire home where there is probable cause to believe that there is relevant evidence somewhere in the home, the court illustrated that a warrant can be both broad and still satisfy the particularity requirement. Id. (citing U.S. Postal Serv. v. C.E.C. Servs., 869 F.2d 184, 187 (2d Cir. 1989)). The court therefore upheld the constitutionality of the warrant. The Supreme Court denied Ulbrich’s writ of certiorari.

Orin Kerr’s equilibrium adjudgment theory of the Fourth Amendment argues that as new tools create imbalanced power on either the side of privacy or the side of law enforcement, the Fourth Amendment must adjust to restore its original balance. The introduction of computers and the internet created an immense change in the tools that both criminals and law enforcement use. Without minimizing the significance of Ulbricht’s crimes, United States v. Ulbricht illustrates this dramatic change. While computers and the internet did create new avenues for crime, computer and internet searches—such as the ones employed by the government—do far more to disrupt the Fourth Amendment’s balance.

Contrary to the court’s argument in Ulbricht, searching a computer is entirely unlike searching a home. First, it is easy to remove items from your home, but the same is not true of computers. Even deleted files often linger on computers where the government can access them. Similarly, when law enforcement finds a file in someone’s home, it still does not know how that file was used, how often it has been viewed, or who has viewed it. But computers do store such information. These, and many other differences demonstrate why particularity, in the context of computer searches, is even more important than the court in UIlbricht acknowledged. Given the immense amount of information available on an individual’s electronic devices, Ulbricht glosses over the implications for personal privacy posed by broad search warrants directed at computers. And with the rapidly changing nature of computer technology, the Fourth Amendment balance will likely continue to stray further from equilibrium at a speed with which the courts will struggle to keep up.

Thus, adjusting the Fourth Amendment power balance related to electronic data will continue to be an important and complicated issue. See, e.g., Proposal 2 Mich. 2020) (amending the state’s constitution “to require a search warrant to access a person’s electronic data or electronic communications,” passing with unanimous Michigan Senate and House of Representative approval, then with 88.8% of voters voting yes on the proposal); People v. Coke, 461 P.3d 508, 516 (Colo. 2020) (“‘Given modern cell phones’ immense storage capacities and ability to collect and store many distinct types of data in one place, this court has recognized that cell phones ‘hold for many Americans the privacies of life’ and are, therefore, entitled to special protections from searches.”) (internal citations omitted). The Supreme Court has ruled on a number of Fourth Amendment and electronic data cases. See, e.g., Carpenter v. United States, 138 S.Ct. 2206 (2018) (warrantless attainment of cell-site records violates the Fourth Amendment); Riley v. California, 134 S.Ct. 2473 (2014) (warrantless search and seizure of digital contents of a cell phone during an arrest violates the Fourth Amendment). However, new issues seem to appear faster than they can be resolved. See, e.g., Nathan Freed Wessler, Jennifer Stisa Granick, & Daniela del Rosario Wertheimer, Our Cars Are Now Roving Computers. Is the Fourth Amendment Ready?, ACLU (May 21, 2019, 3:00 PM), https://www.aclu.org/blog/privacy-technology/surveillance-technologies/our-cars-are-now-roving-computers-fourth-amendment. The Fourth Amendment therefore finds itself in eel infested waters. Is rescue inconceivable?

Special thanks to Professor Rozenshtein for introducing me to Ulbricht and inspiring this blog post in his course Cybersecurity Law and Policy!

The “Circuit Split” That Wasn’t

October 25, 2020
Constitutional Law, Criminal Law, Fourth Amendment, Law Enforecement

Sam Sylvan, MJLST Staffer

Earlier this year, the Fourth Circuit punted on an opportunity to determine the constitutional “boundaries of the private search doctrine in the context of electronic searches.” United States v. Fall, 955 F.3d 363, 371 (4th Cir. 2020). The private search doctrine, crafted by the Supreme Court in the 80’s, falls under the Fourth Amendment’s umbrella. The doctrine makes it lawful for law enforcement to “search” something that was initially “searched” by a private third party, because the Fourth Amendment is “wholly inapplicable to a search or seizure, even an unreasonable one, effected by a private individual not acting as an agent of the Government or with the participation or knowledge of any government official.” United States v. Jacobsen, 466 U.S. 109, 113 (1984).

An illustration: Jane stumbles upon incriminating evidence on John’s laptop that implicates John in criminal activity (the “initial private search”), Jane shows the police what she found on the laptop (the “after-occurring” search), and the rest is history for John. But for law enforcement’s after-occurring search to avoid violating the Fourth Amendment, its search must not exceed the scope of the initial private search. “The critical measures [to determine] whether a governmental search exceeds the scope of the private search that preceded it,” United States v. Lichtenberger, 786 F.3d 478, 485 (6th Cir. 2015), include whether “there was a virtual certainty that nothing else of significance was in the [property subjected to the search]” and whether the government’s search “would not tell [law enforcement] anything more than [it] already had been told” or shown by the private searcher. Jacobsen, 466 U.S. at 119.

Of course, the Supreme Court’s holdings from the 80’s that speak to the scope of the Fourth Amendment are often difficult to reconcile with modern-day Fourth Amendment fact patterns that revolve around law enforcement searches of modern electronic devices (laptops; smartphones; etc.). In the key Supreme Court private search doctrine case, Jacobsen (1984), the issue was the constitutionality of a DEA agent’s after-occurring search of a package after a FedEx employee partially opened the package (upon noticing that it was damaged) and saw a white powdery substance.

Since the turn of the millennium, courts of appeals have stretched to apply Jacobsen to rule on the private search doctrine’s application to, and scope of, law enforcement searches of electronics. In 2001, the Fifth Circuit addressed the private search doctrine in a case where the defendant’s estranged wife took a bunch of floppy disks, CDs, and zip disks from the defendant’s property. She and her friend then discovered evidence of defendant’s criminal activity on those disks while searching some of them and turned the collection over to the police, which led to the defendant’s conviction. United States v. Runyan, 275 F.3d 449 (5th Cir. 2001).

There are two crucial holdings in Runyan regarding the private search doctrine. First, the court held that “the police exceeded the scope of the private search when they examined the entire collection of ‘containers’ (i.e., the disks) turned over by the private searchers, rather than confining their [warrantless] search to the selected containers [that were actually] examined by the private searchers.” Id. at 462. Second, the court held that the “police search [did not] exceed[] the scope of the private search when the police examine[d] more items within a particular container [i.e., a particular disk] than did the private searchers” who searched some part of the particular disk but not its entire contents. Id. at 461, 464. Notably absent from this case: a laptop or smartphone.

Eleven years after Runyan, the Seventh Circuit held that the police did not exceed the scope of the private searches conducted by a victim and her mother. Rann v. Atchison, 689 F.3d 832 (7th Cir. 2012) (relying heavily on Runyan). In Rann, the police’s after-occurring search included viewing images (on the one memory card brought to them by the victim and the one zip drive brought to them by the victim’s mother) that the private searchers themselves had not viewed. Id. Likening computer storage disks to containers (as the Runyan court did), the Rann court concluded “that a search of any material on a computer disk is valid if the private [searcher] viewed at least one file on the disk.” Id. at 836 (emphasis added). But notably absent from this case like Runyan: a laptop or smartphone.

Two years after Rann, the Supreme Court decided Riley v. California—a landmark case where the Court unanimously held that the warrantless search of a cellphone during an arrest was unconstitutional. Specific reasoning from the Riley Court is noteworthy insofar as assessing the Fourth Amendment’s (and, in turn, the private search doctrine’s) application to smartphones and laptops. The Court stated:

[W]e generally determine whether to exempt a given type of search from the warrant requirement by assessing, on the one hand, the degree to which it intrudes upon an individual’s privacy and, on the other, the degree to which it is needed for the promotion of legitimate governmental interests. . . . [Smartphones] are in fact minicomputers that also happen to have the capacity to be used as a telephone. They could just as easily be called cameras, video players, rolodexes, calendars, tape recorders, libraries, diaries, albums, televisions, maps, or newspapers. One of the most notable distinguishing features of [smartphones] is their immense storage capacity.

573 U.S. 373, 385, 393 (2014). Riley makes crystal clear that when the property at issue is a laptop or smartphone, the balance between a person’s privacy interests and the governmental interests tips heavily in favor of the individual’s privacy interests. In simpler terms, law enforcement needs a warrant to search a laptop or smartphone unless it has an extremely compelling reason for failing to comply with the Fourth Amendment’s warrant requirement.

 

One year after Riley, the Sixth and Eleventh Circuits—armed with Riley’s insights regarding modern electronic devices—decided Lichtenberger and United States v. Sparks, respectively. The two Circuits held that in both cases the police, in conducting their after-occurring warrantless searches of a laptop (Lichtenberger) and a smartphone (Sparks), exceeded the scope of the initial private searches, reaching these conclusions in large part due to Riley. In Lichtenberger, the police exceeded the scope of the initial private search when, without a warrant, they looked at photographs on the laptop that the private searcher had not looked at, despite the private searcher’s initial viewing of other photographs on the laptop. 786 F.3d 478 (6th Cir. 2015). In Sparks, the police exceeded the scope of the initial private search when, without a warrant, they viewed a video within the same album on the smartphone that the private searcher had scrolled through but which the private searcher did not actually view. 806 F.3d 1323 (11th Cir. 2015), overruled on other grounds by United States v. Ross, 963 F.3d 1056 (11th Cir. 2020) (overruling Sparks “to the extent that [Sparks] holds that [property] abandonment implicates Article III standing”).

 

At first glance, Lichtenberger and Sparks seem irreconcilable with Runyan and Rann, leading many commentators to conclude there is a circuit split regarding the private search doctrine: the “container” approach versus the “file”/“narrow” approach. But I disagree. And there is a rather simple explanation for reaching this conclusion—Riley merely heightened Jacobsen’s “virtual certainty” requirement in determining whether law enforcement exceed the scope of initial private searches of laptops and smartphones. In other words, “virtual certainty” is significantly elevated in the context of smartphones and laptops because of the heightened privacy interests at stake stemming from their immense storage capacities and unique qualities—i.e., they contain information and data about all aspects of our lives to a much greater extent than floppy disks, CDs, zip drives, and camera memory cards. Thus, the only apparent sure way for law enforcement to satisfy the private search doctrine’s “virtual certainty” requirement when a laptop or smartphone is involved (and thereby avoid inviting defendants to invoke the exclusionary rule) is to view exactly what the private searcher viewed.

In contrast, the “virtual certainty” requirement in the context of old school floppy disks, CDs, zip drives, and memory cards is quite simply a lower standard of certainty because the balance between privacy interests and legitimate governmental interests is not tipped heavily in favor of privacy interests.

While floppy disks, CDs, and zip drives somewhat resemble “containers,” such as the package in Jacobsen, smartphones and laptops are entirely different Fourth Amendment beasts. Accordingly, the four cases should all be analyzed through the lens that the particular electronic device at issue in each case is most significant because it guides the determination of whether the after-occurring search fell within the scope of the initial private search. Looking at the case law this way makes it so that it is not the container approach versus the file approach. Rather, it is (justifiably) the container approach for certain older electronic storage devices and the file approach for modern electronic devices that implicate weightier privacy concerns.

Hailstorms in Baltimore: The Fourth Circuit’s Opportunity to Create Oversight and Accountability for a Secretive Police Technology

October 17, 2020
Constitutional Law, Fourth Amendment, Human Rights Law, Law Enforecement

Jordan Hughes, MJLST Staffer

The past several months have once again shone a spotlight on the difficulty of holding police and law enforcement accountable for their actions. The American public has become more aware than ever of the unions and structures in place to shield officers from liability. Despite years of DOJ investigations and investigative reporting into the procedures of departments around the country, many regular police practices remain hidden from the public eye. Including the use of secretive new technologies that allow for unprecedented levels of discretion—and unprecedented potentials for abuse.

The Hailstorm is one such dragnet-style electronic capturing device that over 85 federal and state enforcement agencies have used largely in secret for more than two decades. This past spring, the 4th Circuit joined the fledgling ranks of federal courts asked to grapple with constitutional questions raised by the elusive technology. Baltimore police used a Hailstorm in 2014 to locate Kerron Andrews, who had an outstanding arrest warrant. Andrews v. Balt. City Police Dep’t, No. CCB-16-2010, 2018 U.S. Dist. LEXIS 129523, at *4 (D. Md. Aug. 1, 2018). The device enabled Baltimore police to pinpoint the apartment building where Andrews was sitting, despite having been unable to find him using standard location information released to them by his phone carrier. The police never disclosed the device during their surveillance, citing instead a “pen register order” as authorization for its use. A Maryland state court held that the government violated Andrews’ Fourth Amendment rights through use of the Hailstorm, and a state appellate court upheld that decision. Andrews then sued the police department in a federal district court, but the federal court considered the search constitutional and granted summary judgment against him. Andrews appealed.

The 4th Circuit, in Andrews v. Balt. City Police Dep’t, No. 18-1953, 2020 U.S. App. LEXIS 9641 (4th Cir. Mar. 27, 2020), both acknowledged the serious constitutional questions at stake and declined to make a ruling on them due to a lack of information. The district court was directed on remand to make findings concerning the Baltimore Police Department’s practice regarding Hailstorm technology, as well as the extent of constitutional intrusions involved in the search. Whatever the outcome, the 4th Circuit is likely to hear this case again. When it finally does, the court will have to decide how to apply the Fourth Amendment to a technology that may be fully incompatible with the freedom from broad and general searches that it typically guarantees.

What is a Hailstorm?

The “Hailstorm” is a model of “cell site simulator” technology sold by Harris Corporation. Other commonly used Harris models include the “StingRay,” “TriggerFish,” and “KingFish.” Generically, these devices are known as international mobile subscriber identity (“IMSI”) catchers.

IMSI catchers essentially mimic a wireless carrier’s base station, causing cell phones to communicate their unique identifiers and location data to the device even when they’re not in use. They function as a dragnet, capturing the unique numerical identifiers of all wireless devices within a particular area. The technology provides both identification and location data for devices. It is precise enough for law enforcement to narrow a device’s location to six feet, and to identify the exact unit a device is in from outside a large apartment complex. IMSI catchers are also capable of capturing the contents of communications, although there has not been a disclosed instance yet of law enforcement using an IMSI catcher in this fashion. IMSI catchers are small, and can easily be handheld or mounted on vehicles or drones.

What is the concern?

The Hailstorm raises a number of concerns under the Fourth Amendment—the constitutional provision meant to protect Americans from unreasonable searches and seizures. The ACLU, in a 2014 guide for defense attorneys, outlined the major Fourth Amendment questions that arise with the use of any IMSI catcher. These include:

  1. Level of scrutiny: IMSI catchers are almost certainly intrusive enough to violate both reasonable expectations of privacy and property interests, thus giving rise to Fourth Amendment scrutiny. When used in connection with a residence, the devices provide critical details about the inside of the property that constitutes a search under any framework. While the Supreme Court has held that there is no reasonable expectation of privacy on outgoing phone numbers voluntarily sent to a third party, that analysis likely cannot extend to data that gets redirected and captured by a Hailstorm without the phone-owner’s knowledge or consent.
  2. General search: There is an argument that any search conducted by an IMSI catcher constitutes a general search, and thus should be categorically barred by the Fourth Amendment. An IMSI catcher indiscriminately gathers all signaling information from a captured phone, seemingly incompatible with a constitutional requirement that surveillance minimize the collection of information unsupported by probable cause. Further, the dragnet functionality conducts this information grab on all devices in a vicinity, including innocent third parties whom the government lacks probable cause to search.
  3. Inaccurate warrants: When law enforcement does apply for a warrant to use an IMSI catcher, those warrants are very likely inaccurate. Warrant applications, driven by federal policies of non-disclosure, typically either (a) omit the fact that the government intends to use an IMSI catcher, (b) mislead the court by saying the government intends to use less intrusive devices (like a pen register) instead, or (c) fail to provide any information on what the technology is and how it operates. In either scenario, the warrant is predicated on a material omission that deprives a court of its constitutional obligation to balance government interests against intrusions into private rights.
  4. Invalid warrants: If a warrant accurately states law enforcement’s intended use of an IMSI catcher, it may be facially invalid due to the necessarily general nature of the search. The entire purpose of the warrant requirement is to require law enforcement to state with particularity the area to be searched and the persons or things to be seized. It remains an open question whether warrant particularity requirements can ever be compatible with intrusive dragnet surveillance technologies.

A separate and perhaps more troubling concern is the extreme lengths, only recently uncovered, that the government has gone to in order to keep this technology a secret. The federal government uses extensive non-disclosure agreements to prevent federal, state, and even local law enforcement from disclosing any details on the capabilities and usage of IMSI catchers. There have been a couple instances where judges demanded police to disclose possible use of an IMSI catcher at trial. Prosecutors in these instances have voluntarily dropped the evidence, offered plea bargains without jail time, or voluntarily dismissed the case altogether rather than disclose the device’s usage. Law enforcement agents have also demonstrated a willingness to offer alternative explanations for evidence obtained by an IMSI catcher. In one case where the FBI used a StingRay, for example, a discovered email from a special agent read: “we need to develop independent probable cause for the search warrant . . . FBI does not want to disclose the [redacted] (understandably so).”

IMSI catchers in the courts so far

The first reported decision dealing with an IMSI catcher was in 1995. In re United States, 885 F. Supp. 197 (C.D. Cal. 1995). The court, which had difficulty applying current law to the new surveillance technology, demanded that law enforcement develop stronger safeguards before permitting its use. Since 1995, nation-wide police practices of avoiding disclosure of the devices has largely shielded them from the view of courts. More recent orders from even the most tech-savvy magistrate judges suggest that judicial officers across the country still have little exposure to or understanding of IMSI technology. The lack of exposure and understanding is critical to continuing the law enforcement practice of applying for approval to use a “pen register” device.

Among the courts that have been faced with the question of IMSI catcher use, several—including the 7th Circuit in 2016—have declined to answer questions concerning the devices’ constitutionality. United States v. Patrick, 842 F.3d 540 (7th Cir. 2016). In his dissent, Chief Judge Wood described the avoidance strategies of law enforcement as “bad faith” that could justify suppression, and closed by writing that “it is time for the Sting[R]ay to come out of the shadows, so that it can be subject to the same kind of scrutiny as other mechanisms.”

The 7th Circuit ultimately did revisit the question of Sting[R]ays in Sanchez-Jara in 2018. United States v. Sanchez-Jara, 889 F.3d 418 (7th Cir. 2018). That court rejected the “general search” argument and upheld a warrant that referred generally to “electronic investigative techniques” without specifying the use of IMSI catcher technology. The other federal circuits have yet to reach a decision on the issue.

Andrews v. Balt. City Police Dep’t will almost certainly appear before the 4th Circuit again. While the question in that case deals with whether a pen register application can cover use of a Hailstorm device, deeper questions surrounding the constitutionality of a Hailstorm search underlie every aspect of the litigation. The court will be faced with a police department that has a history of abusing discretion, and that has shielded the courts from its use of IMSI catchers for years, in a moment of increased public scrutiny of police practices and procedures. The 4th Circuit thus has a unique opportunity to create a level of increased accountability for law enforcement, and to change the trajectory of police surveillance strategies for years to come.

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