Geofence warrants (Google reverse location)
Reverse warrants
This page is public-interest research. An argument grade is not a court finding. A watchdog page describes the device. It is not proof a Nevada agency bought it or turned a feature on. A product description is not a Nevada practice. Agencies are not merged: the City of Las Vegas Department of Public Safety, the Las Vegas Metropolitan Police Department, the Clark County School District, the City of Reno, and the Nevada Department of Public Safety stay separate. A hotlist hit is not a confirmed crime. Legal review of this page is unverified.
What it does
A geofence warrant asks a company, often Google, for every device that was inside a drawn area during a window of time. The return is a list of devices, not one suspect. Police then narrow the list. EFF describes Fog’s area search as the same kind of request aimed at a broker instead of Google.
Privacy watchdog concerns
- Electronic Frontier Foundation. Real-Time Location Tracking. EFF says police use purchased location data either to follow one device or to list every device inside a drawn area. EFF describes that area search as the equivalent of a geofence warrant. This is EFF’s description. It is not proof a Nevada agency ran such a query.
- Electronic Frontier Foundation. Fog Data Science Puts our Fourth Amendment Rights up for Sale. EFF says Fog sells phone-location data to police and that an area search is the equivalent of a geofence. EFF says a warrant should be required to look up one device and that dragnet area searches raise a Fourth Amendment problem. EFF says location data cannot be anonymized. This is EFF’s argument. Carpenter is not a holding about Fog.
Constitutional issues
Analogical constitutional argument
Fourth Amendment, Nevada Constitution art. 1, § 18
Warrant practice not established for a Nevada agency
Geofence warrants (Google reverse location): No Nevada geofence warrant or broker area query is in this build. Carpenter does not become a geofence holding by analogy. Spurlock does not decide a Google reverse-location warrant, and it is not a Ninth Circuit holding.
- Carpenter v. United States, 585 U.S. 296 (2018). Analogical constitutional argument. United States Supreme Court. Carpenter required a warrant for one person’s historical cell-site location information in the circumstances addressed. A geofence that returns every device in a place and time is a different request. The analogy is not the holding.
- United States v. Spurlock, 778 F. Supp. 3d 1136 (D. Nev. 2025). Analogical constitutional argument. Federal district court. Not circuit precedent.. Spurlock is a district-court tower-dump order, not a geofence holding and not a Ninth Circuit holding. Suppression was denied.
Statutes attached to read, not findings.
- NRS Chapter 239. Nevada public-records law is the route to ask for contracts, policies, and logs. Citing it is not a finding that a surveillance practice is unlawful.
- Nevada Constitution art. 1, § 18. State search-and-seizure provision. This page does not quote the section. No section anchor was verified. It is listed only where a search question is actually implicated.
- 42 U.S.C. § 1983. A civil remedy for a deprivation of federal rights under color of state law. It is not a warrant statute, and it does not itself make a surveillance practice unlawful.
Nevada use
Not documented on this page.
No Nevada geofence is documented. Spurlock’s tower dump is a different card.
See also: Bulk location queries; Tower dumps; Fog Data Science
Next record
Geofence warrants (Google reverse location): Request geofence warrants from each agency. None is on file here.
All devices. A document workflow for this page is not built. The arrest correction form is not a surveillance-document inbox. Corrections and source documents for this page follow the corrections policy. Corrections policy.