"Because the world isn't scary enough as it is, researchers from Israeli's Ben-Gurion University have developed a way to eavesdrop on conversations by analyzing the vibrations off a light bulb. They call the technique "lamphone" and say anyone with a laptop, a telescope, and a $400 electro-optical sensor can do it.
This is the kind of thing that would normally worry me, but I mostly just pity the spy that has to listen to the sounds of my lonely sobbing, occasionally broken up by the slurping of SpaghettiOs. Look, Mr. Spy, you don't even have to use my light bulb. Just join me at the dinner table and save yourself the trouble.
Keep going for the full research video."
Apparently using a laser against a window can work just as well, but its still an amazing method.