A post just in case nobody knows about it. This isn’t a conspiracy post, it can be done, the video link is there by Cyb3rMaddy to explain it more thoroughly. It isn’t new tech, it has been around for more than 10 years. It is just crazy to think that somebody can somehow tap into it, maybe your ISP. Who knows how this is being used today. Since there are no cameras on routers, it is unregulated. Your ISP can theoretically use your home Wi-Fi router to track your movements. By analyzing how your body and walls disrupt and reflect wireless signals a technology known as Wi-Fi sensing, AI models can map exactly where you are, what you’re doing, and even your posture. This is wild to think about, I am guessing regular people don’t know this, but it can happen. Since this can be done, somebody can use it against you. It can even detect human breathing rhythm and heart rate. Sitting at home and unaware. Your cell phone can be used as an Wi-Fi access point. Another example is your smart fridge that has Wi-Fi, it does send back data to somewhere anyway. Like when you run out of food or something. I would never get one of those, personally. I totally understand those people that just want to move to a cabin in the woods somewhere.
This requires ancillary hardware that isn’t present on wifi routers, and then it also requires wifi devices spread around the place to provide a signal source for human bodies to distort, and then it requires significant computational hardware that also isn’t present in common home wifi routers.
Not to say that the general method can’t be used for basic presence detection - Philips Hue ZigBee devices can use the variations in the background signal strength of ZigBee devices they can see around them to infer that someone is in a room, so they can switch lights on/off automatically. But it requires multiple devices in a room for it to work reliably and they need calibration as well.
It was shown using a cheap ESP-32 board. Hell, someone could hack your smart TV if they really wanted to. Now, the 802.11BF Wi-Fi sensing capability is being integrated within newer routers. Your ISP can likely detect your movements and presence because the IEEE 802.11bf standard enables Wi-Fi sensing. I always question what ways we are being spied on. There is a reason the US banned all new foreign made routers.