Comment by transpute

Also possible with open firmware on low-cost ESP32 devices, https://wrlab.github.io/Wi-ESP/ & https://github.com/StevenMHernandez/ESP32-CSI-Tool

But there's a big difference in custom firmware used in a few products and IEEE standardization in every new WiFi access point.

We need more funding for countermeasures, https://ans.unibs.it/projects/csi-murder/

> Imagine that someone wants to illegally track the position of a person inside a laboratory, for instance to measure how much time is spent doing different activities at different desks, as depicted in the upper picture. How much effective can this attack be? ... With CSI-MURDER, the localization becomes impossible because results will seem random, thus preserving the person privacy without destroying Wi-Fi communications.

400+ (!) papers on wireless sensing, over the last decade https://dhalperi.github.io/linux-80211n-csitool/ & https://groups.csail.mit.edu/netmit/sFFT/soda_paper.pdf & https://dspace.mit.edu/handle/1721.1/103715