“We developed a deep neural network that maps the phase and amplitude of WiFi signals to UV coordinates within 24 human regions. The results of the study reveal that our model can estimate the dense pose of multiple subjects, with comparable performance to image-based approaches, by utilizing WiFi signals as the only input.”
They bounce a laser off the glass and can hear what’s happening in the room by capturing the vibrations of the glass. I seem to remember the US embassy was caught spying on the Canadian Prime Minister using this technique.
MIT used a high speed camera to reconstruct sound vibrations from objects behind soundproof glass, such as a bag of chips, water in a glass, and a plant. That was in 2014.
https://news.mit.edu/2014/algorithm-recovers-speech-from-vibrations-0804
Yep I have read that sensitive buildings are now built with a hallway ringing the building and offices further inside, so the rooms where classified things are discussed don’t have windows accessible by outside lasers.