Can Spy On:
Anybody with a window.
How It Does It:
Here’s the thing about “bugs,” even if they’re attached to living cockroaches. They have to emit radio waves in order to transmit their signal back to the listeners, which means they’re pretty easy to detect. With the right tools you could scan your apartment right now to see if the feds are listening in.
All they need is a laser microphone. Sound is nothing more than vibrations created in the air. Your thin windows vibrate ever so slightly with every sound (the same principle that lets a certain pitch of voice break glass). So if somebody outside your house can capture that vibration, they can “hear” what’s being said quietly inside the room.
It’s very easy to do. All they need to do is fire a laser at the glass at an angle, and set up a second device to “catch” the reflecting beam. As you talk, the sound wiggles the window, which makes the beam bounce. The listening device can interpret those bounces and translate them back into sound.
Of course, this kind of expensive, high-end device is only available to spy agencies… oh, wait, no: Here’s a guide on how anyone can make their own laser listening device with stuff you can easily buy off the shelf.
But you’ll see this laser beam firing through your window, right? And probably see the red dot on your wall and assume there’s a sniper out there? Not quite. The device doesn’t need visible light to work. You’ll never know they’re doing it. Isn’t science awesome?