WiFi Sensing is part of Wi-Fi 7 and present in most recent laptops and smartphones. Local NPU machine learning can be combined with WiFI radar. Malware can attack phone and radio basebands and exploit this capability. It can uniquely fingerprint human biometrics, measure breathing rate, record keystrokes and more. Thousands of academic papers have been published in the last 15 years on "device free wireless sensing", before the capability was ratified by IEEE as 802.11bf. It's being rolled out commercially. Mitigations include drywall or insulation with a layer of RF shielding.
"Xfinity using WiFi signals in your house to detect motion", 500 comments, https://news.ycombinator.com/item?id=44426726#44427986
"Wi-fi signal tracks heartbeat without wearables", 80 comments, https://news.ycombinator.com/item?id=45488908
2022 laptop demo of respiration sensing, https://www.intel.com/content/www/us/en/research/respiration... | https://community.intel.com/t5/Blogs/Tech-Innovation/Client/...
2025 biometric signature, https://www.theregister.com/2025/07/22/whofi_wifi_identifier...
> Researchers.. developed.. a biometric identifier for people based on the way the human body interferes with Wi-Fi signal propagation.. CSI in the context of Wi-Fi devices refers to information about the amplitude and phase of electromagnetic transmissions.. interact with the human body in a way that results in person-specific distortions.. processed by a deep neural network, the result is a unique data signature.. [for] signal-based Re-ID systems