Researchers Demonstrate How Roadside Cameras Can Track You Through Your Phone
Security researchers have demonstrated a new surveillance technique that can link mobile phones and Bluetooth signals to vehicle license plates through roadside cameras, significantly expanding the tracking capabilities of existing infrastructure.
The approach works by capturing wireless signals emitted by devices inside vehicles—including smartphones, smartwatches, and Bluetooth accessories—at the same time as photographing the license plate. These signals can then be cross-referenced with the plate, creating a persistent identifier that follows the vehicle and its occupants across multiple camera locations.
Privacy advocates have raised concerns about the implications of such technology. While traditional license plate readers primarily track vehicles, this technique effectively extends surveillance to individuals by associating their personal devices with a specific car. This could allow authorities or other actors to maintain detailed records of a person's movements without their knowledge.
The technology reportedly leverages the fact that most people carry Bluetooth-enabled devices nearly everywhere they go, and these devices continuously emit identifying signals. Even when Bluetooth is not actively in use, many devices remain discoverable or emit low-energy beacons that can be captured.
Experts note that defending against this type of tracking is challenging, as it requires users to either leave their devices behind or employ signal-blocking measures—a practical difficulty for most people.
The research highlights an ongoing tension between expanding surveillance capabilities and individual privacy rights, particularly as the infrastructure for such tracking already exists in many cities through traffic cameras and smart city sensors.