Israeli scientists have found a way to listen to what someone is saying in a room more than 80 ft away - by pointing a telescope at a lightbulb.
Ben Nassi, a security researcher at Ben-Gurion University, led the study into the spyware, which requires a laptop and equipment costing under £1000.
The new invention has been called the "lamphone".
After a lightbulb is touched by soundwaves, the surface vibrates and the resulting light emissions are picked up by sensors.