I’ve heard you can use a chip bag to the same effect.
Anything light/thin enough to resonate at vocal frequencies that can reflect a laser (without altering polarization) will work.
I do remember an experiment, using a chip bag, where university researchers were able to extract audio from a video of a chip bag. I believe they were mapping the intensity of the various specular highlights on the bag and playing the audible frequencies. It was muddied and choppy but intelligible.
Even further, your location and time of recording can be roughly estimated based on audio recordings. It’s called Electrical Network Frequency analysis. I forget the specifics, but it had something to do with the frequency change of the power grid (the hum of which can be picked up in some audio recordings, or inadvertently captured as noise from the audio equipment). They can take the recording, determine how the frequency shifted during the recording (corresponding to grid conditions at the time of recording) and compare them to historical data from various utility monitoring stations looking for matches. wiki: https://en.wikipedia.org/wiki/Electrical_network_frequency_analysis
It’s also possible to see what’s on a monitor’s display through processing the EM emissions called Van Eck phreaking.
There’s an entire spectrum of similar attacks: https://en.wikipedia.org/wiki/Tempest_(codename)
Anything light/thin enough to resonate at vocal frequencies that can reflect a laser (without altering polarization) will work.
I do remember an experiment, using a chip bag, where university researchers were able to extract audio from a video of a chip bag. I believe they were mapping the intensity of the various specular highlights on the bag and playing the audible frequencies. It was muddied and choppy but intelligible.
Even further, your location and time of recording can be roughly estimated based on audio recordings. It’s called Electrical Network Frequency analysis. I forget the specifics, but it had something to do with the frequency change of the power grid (the hum of which can be picked up in some audio recordings, or inadvertently captured as noise from the audio equipment). They can take the recording, determine how the frequency shifted during the recording (corresponding to grid conditions at the time of recording) and compare them to historical data from various utility monitoring stations looking for matches. wiki: https://en.wikipedia.org/wiki/Electrical_network_frequency_analysis