Researchers affiliated with Ben-Gurion University of the Negev and the Weizmann Institute of Science report that hackers can now eavesdrop on individuals from 80 feet away or more, using a standard lightbulb.

Granted, there are compounding factors at play, such as whether or not any curtains or lampshades interfere with the visibility of the lightbulb. Additionally, the thickness of the glass, and the output of the light can affect eavesdropping success rates.

So, how does this trick work?

When people speak, or play music, air pressure hits the outside of a lightbulb. These small fluctuations in air pressure, as observed using an electro-optical telescope sensor, allow for the identification of sounds.

“We…isolate the audio signal from the optical signal,” the researchers stated.

While perhaps not the simplest feat to pull off, in theory, hackers could use this method to obtain credit card numbers and other sensitive information. All of the materials required for the hack –a laptop, telescope, microphone and remote electro-optical sensor- are available for less than $1,000.

For technical details on this mind-boggling security discovery, read the research paper. The information is due to be presented at the Black Hat security conference, later this year.

PS. If you’re worried about becoming a target, just draw your curtains.