In the 1992 movie Sneakers, the main characters try to spy on a target’s computer keyboard, but their view is blocked by a surprise entrance. Fast forward to the present, hacker Samy Kamkar is set to unveil his DIY laser-based surveillance system at Defcon. With this system, Kamkar can spy on a laptop from afar, detect vibrations, and pick up sounds through windows. By bouncing an infrared laser off a reflective portion of the laptop, Kamkar can reconstruct almost every typed character. His innovative laser microphone setup can also record sounds in a room. Kamkar’s goal is not just to spy, but also to push the boundaries of physics-based hacking, challenging the traditional concept of computer security.
https://www.wired.com/story/infrared-laser-microphone-keystroke-surveillance/