From Daily Mail:
Using a wireless transmitter fitted behind a wall, computer scientists have developed a device that can map a nearby room in 3D while scanning for human bodies. Using the signals that reflect off these people, the device creates an accurate silhouette (pictured) and can even use this silhouette to identify who that person is.
The device is called RF Capture and it was developed by researchers at MIT’s Computer Science and Artificial Intelligence Lab (CSAIL).
Read more on Daily Mail.