Ordinary WiFi networks could quietly become powerful surveillance tools, allowing people to be identified without cameras, special sensors, or even carrying a connected device. Researchers showed that unencrypted signals routinely exchanged between WiFi devices and routers can be used to create radio-based images of people and recognize them within seconds. In tests involving 197 participants, the system identified individuals with nearly 100% accuracy, even from different angles and regardless of how they walked.
The article was very clear that this isn’t fingerprinting your devices. You could have zero devices, but you walk into a café and other people’s devices are all screaming radio waves, including BFI data, which bonuses off your physical body, forming an image of you
That unencrypted BFI data can then be listened-to by a nearby attacker who would process the data in a ML algorithm, and identify you with near 100% accuracy.
That’s what the article said.