A 150-Meter Fishing Net: Reconciling the Third-Party Doctrine With The Realities of Geofence Warrants

Introduction

“Allow [App Name] to access this device’s location?” This routine prompt, issued by countless tech corporations, is rarely understood as a potential waiver of constitutional protections. Yet the rise of geofence warrants transforms the single tap into a mechanism through which law enforcement can treat vast numbers of individuals as potential suspects. In legal terms, geofence warrants are “reverse warrants,” where law enforcement requests locational data for all devices within a specific geographic area, during a particular timeframe, from technology companies like Google to identify potential suspects [1]. Unlike traditional warrants that target a specific suspect, geofence warrants begin with a crime scene and cast a “dragnet,” effectively seizing data of hundreds of innocent civilians who were in the vicinity. The use of geofence warrants has increased exponentially since law enforcement first issued them to Google in 2016 [2]. According to the most recent data released, the number of geofence warrants received by Google increased from 982 in 2018 to 11,554 in 2020 [3].

Pertaining to warrants, the Constitution promises protection against unreasonable searches and seizures, guaranteeing the issuance of a warrant founded upon probable cause [4]. The Constitution emphasizes the importance of having the “place to be searched, and the persons or things to be seized” described with particularity – a requisite unfulfilled by the lack of a particular suspect driving geofence warrants. The legal question of whether law enforcement’s use of geofence warrants violates the Fourth Amendment’s particularity requirement, with its lack of probable cause, is further complicated by the Third-Party Doctrine. The doctrine is a legal principle that denies constitutional protection for information voluntarily provided to third parties, viewed as no longer subject to a reasonable expectation of privacy under the Fourth Amendment [5]. Examples include bank records, IP addresses, and subscriber information that grants the government the power to access the data without an issued warrant. In the context of geofence warrants, law enforcement has historically relied on this doctrine to argue the voluntary condition under which users share their location history with technology companies, legitimizing its issuance under the Fourth Amendment. In evaluating the nature of geofence warrants and the nature of protection granted by the Fourth Amendment, this essay argues that geofence warrants constitute an unconstitutional expansion of the Third-Party Doctrine, violating the Fourth Amendment’s particularity requirement by authorizing broad, suspicionless searches.

The Question of Particularity

The Fourth Amendment’s particularity requirement– mandating that warrants clearly specify the places to be searched and the “persons or things to be seized” – raises serious concerns regarding the constitutionality of geofence warrants. Adopted in 1791 in response to the abuses of “general warrants” in England and the “writs of assistance” in the American colonies, the Amendment was designed to prevent broad, exploratory searches conducted without individualized suspicion [6]. In its most practical application – Nardone v. United States (1939) – the U.S. Supreme Court ruled that any evidence obtained indirectly from an illegal search or seizure was inadmissible in court [7]. While having specifically dealt with evidence acquired from illegally wiretapped messages, the court’s ruling solidified the Fourth Amendment’s protection of individual privacy. By ensuring that any evidence derived from an illegal search – not just the search itself – is deprived of its utility in court, the case stressed the importance of an authorized warrant.

Within the probable cause framework of warrant authorizations, the Constitution explicitly iterates the particularity requirement, ensuring a narrow scope of the issued warrants to be strictly limited to the specific places, persons, or things described. Geofence warrants, by their functionality, adhere only to a certain constitutional threshold of the particularity requirement. While specifying the geographic boundaries and timeframes of data to be searched, the persons to be seized are unknown at the time of the warrants’ enactment. Even warrantless searches and seizures deemed legitimate under the law require the officer to observe unusual conduct that leads them to raise reasonable suspicion of crime before stopping suspects to make reasonable inquiries [8]. For geofence warrants, the individualized suspicion required before initiating searches and seizures is rendered obsolete as law enforcement accesses the location data of thousands of innocent bystanders who were within a geofence [9]. The absence of particularity of persons being identified subjects an entire group of citizens to government scrutiny based solely on their past physical proximity to a crime scene. This reality contradicts the core constitutional prohibition of broad, exploratory searches, as well as the exploitation of such methods to produce evidence of a crime.

Furthermore, more recent cases highlight the indispensability of a properly issued warrant in determining the legitimacy of obtained evidence. In Carpenter v. United States (2018), the U.S. Supreme Court ruled the obtaining of cell-site location information without a warrant to be unconstitutional, even under the Third-Party Doctrine that categorized such information as voluntarily provided [10]. Recognizing the inescapability factor of modern technology, the Supreme Court significantly limited law enforcement’s reliance on the traditional Third-Party Doctrine for location data, still subjecting attempts to access personal data to the Fourth Amendment’s warrant requirements. Moreover, as a direct response to the use of geofence warrants, in People v. Dawes (2022), the San Francisco Superior Court suppressed evidence obtained through a geofence warrant by classifying such findings as an unconstitutional violation of the Fourth Amendment [11]. The charge of robbery was based on cell phone location and account data gathered from Google with a geofence warrant. In suppressing such evidence, the Court effectively emphasized the constitutional frailty of geofence warrants, which disregarded the particularity, scope, and individualized suspicion required by the Fourth Amendment. A digital dragnet cast by a geofence warrant undermines the strict particularity requirement of the Fourth Amendment, irreconcilable with a mechanism that treats physical proximity as a proxy for criminal culpability.

Concerns Regarding Accuracy and Probable Cause

Along with its tension with the Fourth Amendment’s guarantee of privacy, geofence warrants raise accuracy concerns, particularly regarding potential false positives that may occur when data erroneously implicates innocent bystanders as suspects. When accuracy is compromised, it weakens the reliability basis of probable cause to seize the private data of thousands of citizens. The question of reliability is further captured in the fact that digital data obtained may be more erroneous than authorities believe it to be. For example, GPS errors, app inaccuracies, and data interpretation issues are highly likely to lead to false conclusions, exposing the inherent fallibility of location data to base criminal suspicion [12]. Moreover, many digital and geofence warrants cast extremely wide nets that can extract data from people whose whereabouts may not even have been physically adjacent to the scene of the crime. Considering its limitless search potential, its estimation, which aims for a 68% confidence interval – in accordance with Google’s location data estimation – posits a high likelihood of false negatives and false positives that can have drastic implications for those impacted [13].

To exemplify, in 2018, Jorge Molina, a 23-year-old man at the time, was wrongfully arrested and jailed for six days on suspicion of murder based on law enforcement’s use of location data obtained from a geofence warrant that supposedly positioned him within the crime scene [14]. As it turns out, a device – not operated by Molina himself – was logged into Molina’s Google account and was detected within the geofence, falsely identifying him as a suspect based on data that lacked a definitive link to his physical location. Such a disconnect highlights the risks and limitations of relying on a set of data that is inherently designed to capture digital accounts rather than persons, subordinating a constitutional due process to a statistically flawed estimation of culpability. This accuracy concern fundamentally weakens the evidentiary foundation required to establish probable cause, as geofence warrants cannot ever be truly particularized if they rely on data that is designed to include innocent bystanders on a 32% chance of error – a standard far too low to justify the seizure of private location history central to geofence warrants.

The Role of The Third-Party Doctrine

In the evaluation of the legality of geofence warrants, it is important to acknowledge that, under the traditional interpretation of the Third-Party Doctrine, individuals generally lose a reasonable expectation of privacy in information that they voluntarily offer to a third party. In the United States v. Miller (1976) case, the U.S. Supreme Court ruled against Miller, stating that bank records are information given voluntarily to a third-party corporation that the government can access without a warrant [15]. The ruling served as a cornerstone of the Third-Party Doctrine, as Miller’s private banking records – checks, deposit slips, and financial statements – were deemed to have been voluntarily conveyed to the bank and its employees [16]. In upholding the Third-Party Doctrine, the ruling generalized information shared with a third party to assume the risk that it may be shared with the government. Location data, which individuals share with service providers like Google, has been regarded as falling into such a category. As it combines user-granted consent through app permissions and account settings with technical signals, it is viewed as constituting a voluntary disclosure of personal information, mirroring the risks of bank records when it comes to being accessed by the government without an authorized warrant [17].

However, the Third-Party Doctrine, established by the U.S. Supreme Court during the 1970s, fails to account for modern technology, particularly the diminished voluntariness of providing one’s location information to third-party corporations out of necessity [18]. Similar to the United States v. Miller (1976) case, Smith v. Maryland (1979) posited a ruling that the Third-Party Doctrine extended to telephone metadata, where individuals’ private interest in phone numbers dialed is nullified by the act of knowingly sharing such information with the phone company [19]. The use of such records was not ruled an unconstitutional violation of the legitimate expectation of privacy under the Fourth Amendment because they were available to the third-party corporation – the phone company. However, taking into account the advancements in modern technology, it appears highly impractical to participate in modern society without revealing personal data to third-party service providers [20]. The voluntariness of providing location data to Google is an argument that is difficult to make, given its scarce alternatives. If an individual has no choice but to provide their location data for essential daily functioning, is that data still fulfilling the voluntary conveyance under the Third-Party Doctrine needed to legitimize the use of such information without an authorized warrant?

Ongoing litigation involving geofence warrants illustrates this tension, as shown by the ongoing Chatrie v. United States (2026) case regarding the constitutionality of geofence warrants. In particular, the geofence warrant compelled Google to disclose the location history of users who were within a 150-meter radius of the incident – a geofence that is as big as several football fields [21]. Lower courts have denied a motion to suppress evidence from a geofence warrant in the case in question by citing different reasons that failed to resolve the question of its constitutionality [22]. The question of whether the execution of the geofence warrant to identify Chatrie as the suspect violated the Fourth Amendment demonstrates the growing tension of applying a 50-year old legal doctrine to 21st-century surveillance. Scheduled to hear oral arguments in late April 2026, the U.S. Supreme Court will address the first major challenge to the constitutionality of the increasing use of geofence warrants [23]. In addressing Chatrie v. United States (2026), the diminished relevance of the Third-Party Doctrine is clearly illustrated, pushing the courts and law enforcement to recognize the technical realities that undermine the legal grounds for geofence warrants. However, treating geofence warrants as outside the scope of the Fourth Amendment may potentially reinforce the continued dominance of the Third-Party Doctrine that normalizes broad digital dragnets as procedural tools of investigation [24].

Absence of A Neutral, Detached Magistrate

Beyond the constitutionality of the scope of the search itself, geofence warrants fundamentally bypass the core of the Fourth Amendment by delegating the authority of a neutral, detached magistrate – a judge or authorized court official – to issue authorized warrants to law enforcement’s discretion. Based on the constitutional requirement of the Fourth Amendment, an inference of probable cause must be drawn by a judicial officer who is not actively engaged in law enforcement activities [25]. Such a requirement ensures that search and seizure warrants are protected through objective oversight that evaluates the given evidence and justifies the state’s interest in a temporary breach of privacy. Taken together, the authorization of warrants under a neutral, detached judicial officer works to prevent competitive bias within law enforcement officers, ensure probable cause, and uphold the separation of powers that protect the fundamental rights to privacy.

Considering such essential conditions, geofence warrants fail to obtain justification under probable cause evaluated by a neutral, detached judicial officer – instead vesting such authority in the discretion of those distinctly involved in the investigation. In Chatrie v. United States (2026), the government’s search warrant unconstitutionally granted authority to the officers and Google to determine the parameters and identifying information obtained [26]. Such a measure demonstrated a clear departure from the prescribed role of a neutral magistrate to evaluate presented evidence, describe the particularity of the search, and authorize the warrant.

Nonetheless, the unconstitutional nature of geofence warrants does not remain specific to Chatrie v. United States (2026). All issued geofence warrants undergo a three-step process that inherently bypasses the gatekeeping role of a judicial officer. First, law enforcement sends a geofence warrant to a third-party corporation, such as Google, to request an anonymized list of users in a specified geographic area – geofence – and time frame [27]. Next, law enforcement narrows down the list of devices by compelling further contextual location information from the third party, which includes location data that is outside of the original time frame [28]. Lastly, law enforcement will compel personal identifying information, such as account holder names and email addresses associated with the devices deemed relevant under the two initial steps taken.

As demonstrated, the three procedural steps are solely dependent on the subjective discretion of law enforcement, where it is not only the occurrence of the search and seizure that is being decided, but the parameters of the search itself. The bypassing of a neutral judicial officer’s gatekeeping role holds immense consequences for potential overreach, where the normalization of mass surveillance sets a precedent, where proximity to a scene of crime overrides culpability, allowing for a retroactive justification of a search. The complete circumvention of the limits set by the Fourth Amendment imposes serious implications for civil liberties. The transition to a dragnet surveillance signals a potential future of an eroded presumption of innocence – one that propagates “guilt by proximity” logic that overrides the constitutionally vested right to individual privacy [29].

Conclusion

The rise of geofence warrants ultimately reveals an ongoing dilemma that weighs efficiency against the constitutional requisites required to issue an authorized warrant. The inherent nature of geofence warrants appears to mirror the general warrants and writs of assistance of the 18th century, which the founding fathers particularly sought to abolish. The lack of particularity and probable cause, concerns regarding accuracy, and the collapse of the separation of powers in the authorization process collectively transform geofence warrants into an instrument of unconstitutional overreach, even when examined under cases of exceptions granted under the Third-Party Doctrine.

Taken as a whole, geofence warrants constitute an unconstitutional expansion of the Third-Party Doctrine that violates the Fourth Amendment’s particularity requirement by authorizing broad, suspicionless searches. Such a tension may raise concerns regarding the evolving overreach of law enforcement’s capacity to violate individual privacy, particularly in an era where data and technology are increasingly becoming indiscernible aspects of modern life. The Fourth Amendment, in addition to the Third-Party Doctrine, must recognize the context to which the doctrine is applied, and ensure that the decision to participate in modern society does not constitute a waiver of constitutional protection. Examining the ongoing discourse surrounding the limits of law enforcement in the face of technological advancement, the proliferation of geofence warrants signals a fundamental erosion of the longstanding principles of the Fourth Amendment, forecasting a future in which the protection of individuals’ privacy becomes a privilege rather than an inherent right.

Footnotes

[1] National Association of Criminal Defense Lawyers, Geofence Warrants (2025), https://www.nacdl.org/Content/Geofence-Warrants

[2] Prathi Chowdri, Emerging Tech and Law Enforcement: What Are Geofences and How Do They Work? (2024), https://www.lexipol.com/resources/blog/emerging-tech-and-law-enforcement-what-are-geofences-and-how-do-they-work/

[3] Queenie Wong, Police like using Google data to solve crimes. Does that put your privacy at risk? (2023), https://www.latimes.com/politics/story/2023-07-24/police-google-data-geofence-warrants-california-lawmakers-abortion-legislation

[4] Constitution Annotated, Fourth Amendment (2019), https://constitution.congress.gov/constitution/amendment-4/

[5] Institute for Justice, Third Party Doctrine (2021), https://ij.org/issues/ijs-project-on-the-4th-amendment/third-party-doctrine/

[6] National Archives, Constitutional Amendments – Amendment 4 – “The Right to Privacy” (2026), https://www.reaganlibrary.gov/education/lesson-plans/high-school/constitutional-amendments/constitutional-amendments-amendment-4

[7] Nardone v. United States, 308 U.S. 338 (1939)

[8] United States Courts, What Does the Fourth Amendment Mean? (2024), https://www.uscourts.gov/about-federal-courts/educational-resources/about-educational-outreach/activity-resources/what-does-fourth-amendment-mean

[9] Center for Democracy and Technology, CDT Calls for SCOTUS to Reject Overbroad Geofence Warrant in New Amicus Brief (2026), https://cdt.org/insights/cdt-calls-for-scotus-to-reject-overbroad-geofence-warrant-in-new-amicus-brief/

[10] Carpenter v. United States, 585 U.S. ___ (2018)

[11] People v. Dawes, No. 19002022 (2022)

[12] The Law Office of David A. Webster, Challenging Digital and Geofence Warrants (2026), https://thewebsterlawoffice.com/2026/01/challenging-digital-and-geofence-warrants/

[13] Columbia Undergraduate Law Review, Warrants and the Risks of Chatrie (2025), https://www.culawreview.org/journal/mapping-the-future-of-surveillance-geofence-warrants-and-the-risks-of-chatrie#:~:text=Taking%20that%20geofences%20are%20a,the%20original%20geofence%20at%20all.

[14] Phoenix New Times, Avondale Man Sues After Google Data Leads to Wrongful Arrest for Murder (2020), https://www.phoenixnewtimes.com/news/google-geofence-location-data-avondale-wrongful-arrest-molina-gaeta-11426374/

[15] United States v. Miller, 425 U.S. 435 (1976)

[16] Every CRSReport, The Fourth Amendment Third-Party Doctrine (2014) https://www.everycrsreport.com/reports/R43586.html

[17] Google, Consent Mode Overview (2024), https://developers.google.com/tag-platform/security/concepts/consent-mode#:~:text=a%20general%20model.-,Advanced%20consent%20mode,Learn%20more%20about%20tag%20behavior.

[18] Institute of Justice, Third Party Doctrine. supra note 5.

[19] Smith v. Maryland, 442 U.S. 735 (1979), https://supreme.justia.com/cases/federal/us/442/735/

[20] Shawn Bass, The Outdated Third-Party Doctrine and the Need for Modernization (2021), https://digitalcommons.nyls.edu/cgi/viewcontent.cgi?article=1759&context=nyls_law_review#:~:text=that%20it%20lies%20at%20the,Id.&text=before%20%5Bthe%20Court%2C%5D%E2%80%9D,in%20other%20contexts.%E2%80%9D%29.

[21] ACLU, United States v. Chatrie (2026), https://www.aclu.org/cases/united-states-v-chatrie

[22] John Villasenor, Supreme Court agrees to hear a Fourth Amendment case regarding geofence warrants (2026), https://www.brookings.edu/articles/supreme-court-agrees-to-hear-a-fourth-amendment-case-regarding-geofence-warrants/

[23] BallotPedia, Chatrie v. United States (2026), https://ballotpedia.org/Chatrie_v._United_States

[24] Rudraksh Lakra, Geofence Warrants and the Fourth Amendment After Carpenter: The Stakes in Chatrie v. United States (2026), https://indconlawphil.wordpress.com/2026/02/24/geofence-warrants-and-the-fourth-amendment-after-carpenter-the-stakes-in-chatrie-v-united-states-guest-post/

[25] Legal Information Institute, Amdt 4.5.2 Neutral and Detached Magistrate (2022), https://www.law.cornell.edu/constitution-conan/amendment-4/neutral-and-detached-magistrate

[26] ACLU, Rights Groups to Supreme Court: Reject Privacy-Invasive Geofence Warrants (2026), https://www.aclu.org/press-releases/rights-groups-to-supreme-court-reject-privacy-invasive-geofence-warrants

[27] Library of Congress, Geofence Warrants and the Fourth Amendment (2026), https://www.congress.gov/crs-product/LSB11274#:~:text=Both%20cases%20involved%20warrants%20for,under%20the%20first%20two%20steps.

[28] Prathi Chowdri, Emerging Tech and Law Enforcement: What Are Geofences and How Do They Work?. supra note 2.

[29] Matthew Guariglia, Geofence Warrants and Reverse Keyword Warrants are So Invasive, Even Big Tech Wants to Ban Them (2022), https://www.eff.org/deeplinks/2022/05/geofence-warrants-and-reverse-keyword-warrants-are-so-invasive-even-big-tech-wants#:~:text=According%20to%20a%20Deeplinks%20blog%20post%20by,the%20limits%20set%20by%20the%20Fourth%20Amendment