A surveillance firm with deep ties to law enforcement has developed a technology to wirelessly identify and make a database of Bluetooth devices like iPhones. This will be used to spot suspects traveling together, and may track protestors heading to marches.
Automatic License Plate Recognition (ALPR) is already common worldwide, and Australian police even have a CarPlay app that identifies nearby cars. But now according to 404 Media, a firm is working to fit more sensors to existing camera systems as part of a scheme to give civil liberties groups apoplexy.
Leonardo US Cyber and Security Solutions is marketing technology it calls SignalTrace, which it says is to “identify people of interest by the signals emitted from their electronic devices they travel with, such as fitness trackers, smartwatches, RFID tags, and local signals from their mobile phones.”
SignalTrace sensors collect data from Bluetooth and Wi-Fi, as well as RFID tags. It categorizes the signals by device and links it to the data shot by ALPR cameras.
The idea is that as well as grabbing all of this data, it can be used to create a digital fingerprint of a person or a group of people. It stores that data for the authorities, but also uses it to track trends, such as when two phones are consistently spotted traveling together.
This “can lead to the discovery of convoys and other movement and travel patterns,” says Leonardo’s official site. Leonardo also claims that it respects individuals’ privacy and does not decrypt or read content from the devices it detects.
Then, too, the firm stresses that this data will only be used when requested by law enforcement. However, there is no mention of Leonardo requiring warrants.
The argument in favor of this is that cars are being driven in public places, and people walk on sidewalks in public, and so there can be no expectation of privacy. But without any state or federal oversight of the system, this is a private company holding personal data and it is bound to be questioned in court.
SignalTrace was previously marketed as the Elsag EOC Plug. Its latest incarnation with the Bluetooth identity scraper appears to be so new that it’s possible no states have yet purchased it.
The company says that SignalTrace’s predecessors, though, have been used by “nearly 4,000 customers in over 25 countries by local, state, and federal law enforcement agencies.”
Civil liberties groups have yet to specifically call out SignalTrace. But in November 2025, the Electronic Frontier Foundation claims that more than 50 agencies tracked protest activities using previous license plate systems.



