One of the most common comments in discussions about automated license plate readers is: “Your cellphone already tracks you, so what’s the difference?” It is a fair question, but the technologies collect information differently and raise different legal questions.
Yes, cellphones can generate location data
Wireless carriers maintain records needed to provide service, and many applications collect location data for navigation, weather, social media, shopping, advertising, and other functions. Depending on settings and permissions, an application may collect location information while it is actively used or while it runs in the background.
Users may have choices such as allowing location only while an application is in use, denying access, disabling location services, or uninstalling the application. But not every form of cellphone location data is meaningfully voluntary. Cell-site records, for example, are generated as a phone connects to the network.
The Fourth Amendment and historical cellphone data
In Carpenter v. United States, 585 U.S. 296 (2018), the Supreme Court held that the government’s acquisition of historical cell-site location information was a Fourth Amendment search and generally required a warrant. The Court declined to treat third-party possession of those records as automatically eliminating constitutional protection.
Recent Supreme Court guidance on geofence warrants
In Chatrie v. United States, 609 U.S. ___ (2026), the Supreme Court held that police conducted a Fourth Amendment search when they obtained Google Location History data through a geofence warrant. The Court vacated the lower-court judgment and returned the case for consideration of whether the warrant met the Fourth Amendment’s probable-cause and particularity requirements.
How ALPR systems differ
ALPR systems photograph vehicles in public view and commonly record a license plate number, date and time, camera location or identifier, and an image of the vehicle. A driver typically has no application permission screen and no practical opt-out when passing a publicly deployed camera.
Repeated observations may be organized into a searchable record of where a vehicle was seen. The U.S. Supreme Court has not yet issued a decision squarely applying Carpenter or Chatrie to a long-term government ALPR database.
Government access and government collection
Cellphone location information is often created and stored by a private communications or technology company, after which the government seeks access. A government ALPR program may instead collect or maintain vehicle-observation records directly or through a contractor acting for the agency. That distinction does not answer every Fourth Amendment question, but it explains why cellphone and ALPR tracking are not legally identical.
Arkansas law
Arkansas’s Automatic License Plate Reader System Act is codified at Ark. Code Ann. §§ 12-12-1801 through 12-12-1808. The statutory framework addresses authorized uses, retention, sharing, reporting, and other requirements. Act 668 of 2025 amended the existing law, including provisions addressing use by private landowners, leaseholders, and commercial businesses.
Primary legal authorities
- U.S. Constitution, Amendment IV.
- Carpenter v. United States, 585 U.S. 296 (2018).
- Chatrie v. United States, 609 U.S. ___ (2026).
- Arkansas Act 668 of 2025.
- Ark. Code Ann. §§ 12-12-1801 through 12-12-1808.
Editorial note: This material is educational and does not provide legal advice. It distinguishes established holdings from unresolved ALPR questions.