If you've been anywhere near the Texas-Mexico border recently with a phone, wireless earbuds, or any other Bluetooth-enabled gadget, there's a chance the feds were keeping tabs on you. At least two counties in the Lone Star State have implemented an incredibly invasive surveillance system that detects and tracks devices by tapping into their Bluetooth signals.

The technology, called TraffiCatch, comes from a German company called Jenoptik. It enables law enforcement to essentially detect any Bluetooth and Wi-Fi signals in the area and log the unique identifiers broadcast by those devices, according to publicly available contract data uncovered by the news outlet NOTUS. By combining that data with automated license plate readers already deployed all along the border, TraffiCatch can theoretically track people's movements, even if they switch vehicles.

Webb County, home to the border city of Laredo, has reportedly had this Bluetooth tracking capability since at least 2019.

The technology works by capturing Bluetooth addresses that are periodically broadcasted by all Bluetooth devices. Some devices use static addresses that never change, making them easy to track persistently. But even gadgets using rotating random addresses can potentially be correlated over time if the person is also carrying a device with a public address.

Jenoptik essentially presents TraffiCatch as a tool for law enforcement to "locate persons of interest related to recorded crimes in the area" by merging vehicle plate data with detected Bluetooth signals. However, the system doesn't discriminate – it can capture any Bluetooth emissions within range from innocent bystanders as well.

This significant expansion of surveillance state overreach in border communities was made possible, in part, thanks to funding from Operation Stonegarden, a federal grant program that incentivizes local police departments to assist border patrol efforts. Last year alone, Stonegarden awarded $90 million to law enforcement agencies in Texas and other border states.

We've already seen how Immigration and Customs Enforcement (ICE) deployed Stingray devices, which masquerade as legitimate cell towers to trick phones into connecting and revealing their locations and identities. Adding Bluetooth tracking into the mix just adds another highly intrusive and indiscriminate monitoring capability to border communities already subjected to disproportionate over-policing.

So the next time you're wandering around these border areas, you might want to consider turning off your gadgets' connectivity features – unless, of course, you're comfortable with Big Brother tracking your movements.