[transpute]

https://www.theregister.com/2025/07/22/whofi_wifi_identifier...

> Researchers in Italy have developed a way to create a biometric identifier for people based on the way the human body interferes with Wi-Fi signal propagation.. can re-identify a person in other locations most of the time when a Wi-Fi signal can be measured. Observers could therefore track a person as they pass through signals sent by different Wi-Fi networks – even if they’re not carrying a phone.. their technique makes accurate matches on the public NTU-Fi dataset up to 95.5 percent.

[Retric]

That’s 95.5% accuracy with a 16 person dataset in a highly constrained environment.

Wi-Fi uses long wavelengths, you can cancel out the noise with one person but crowds are all distorting the same very weak signal here. 5Ghz = 6cm, visible light is 380 to about 750 nanometers.