New Tech Can Link Your Phone And Dog’s Collar To Your License Plate In Maryland

A technical review of the SignalTrace system, designed to pair device signals with license plate data, has found major limitations. The system, which has been spotted in Oxon Hill, Maryland, can link some device signals with plate-reader data and vehicle movements, but its current limitations do not mean its surveillance potential will stay limited. SignalTrace captures publicly emitted Wi-Fi, Bluetooth, and other electronic signals, matching devices that routinely travel together into an “electronic fingerprint.” This can be correlated with a plate number, time, and location when an ALPR camera is present. However, devices do not continuously broadcast stable, identifiable data, and their transmissions occur across different channels, making it difficult for the system to receive certain signals. A sensor must be listening at the right time and frequency, which makes typical TPMS sensors and pet microchips a difficult sell. The system’s flat-panel antenna likely can’t receive the radio frequencies used by most tire-pressure sensors, and pet microchips are generally read from just centimeters away. A Bluetooth pet collar, phone, or set of wireless headphones is much more plausible. While the system may not be as potent as its marketing implies, it still raises concerns about privacy, as a device signature doesn’t need to include a person’s name to become identifying. Repeatedly linking the same phone or watch to a registered vehicle, a home, and other devices can turn a supposedly anonymous pattern into an investigative lead. The technology’s capabilities are likely to improve with better antennas, more sensors, and smarter processing, which could erase some of today’s limitations.