Similar technique around the same time presented at SIGGRAPH:
replyVaguely similar, since electrical wires emit EM fields that are disturbed by human bodies, you can use a special camera to see who's in a building based on those disturbances. I'm not sure how high-fidelity or easy to spoil it is, but this was real technology at least 15 years ago.
replyThis is a feature in modern wifi routers and every single one is capable of detecting presence of multiple people within an apartment. With some training, movement can be distinguished from the data.
replyxfinity is now selling a security product based on seeing people in your home with Wi-Fi signals
replyI recall a HN thread (or maybe it was a github project) about using a similar tactic to figure out keypresses in offices. Very interesting stuff.
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