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Humans can be tracked with unique 'fingerprint' based on how their bodies block Wi-Fi signals
(www.theregister.com)
this post was submitted on 25 Jul 2025
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The resulting image must just basically look like a shadow, I can't imagine that they're going to get much internal detail with Wi-Fi considering that my router's signal practically gets blocked by a piece of cardboard.
This research essentially amounts to, humans can be individually identified with nothing more than low quality x-rays. Well yeah, so what, you can also use visible light and in any situation where you're going to use Wi-Fi to detect someone, it's got to be easier to buy a cheap CCTV camera.
First of all: cardboard does NOT block electromagnetic waves. You need a Faraday Cage for that. And even then, it has to have holes of a certain size to block specific wavelengths/frequencies. It’s why you have a mesh on the door of your microwave for example.
Secondly: they’re not attempting to photograph you. Just identifying your unique signature once would allow them to track your location anywhere where they have the gear installed.
EDIT: I suppose your comment is written in a way that it's not clear whether you're saying certain frequencies absolutely require meshes of a certain size to be blocked or if you're just adding that extra detail about the design of Faraday cages for the hell of it. But...
Original comment: It doesn't have to have holes to block radiation. A continuous sheet blocks all frequencies. A mesh is just nice so we can see through the cage or allow air to pass etc.
From the page you linked: "A Faraday shield may be formed by a continuous covering of conductive material." "... if the conductor is thick enough and any holes are significantly smaller than the wavelength of the radiation."
My bad, a Farady Shield works just as well and it doesn’t need holes. But I was thinking about ways to combat this while posting and a solution involving conductive fabric was going through my head during that moment.