See also this post: https://news.ycombinator.com/item?id=12166332#12170616 https://news.ycombinator.com/item?id=12166332#12170616 Link reproduced for clarity:

See also this post: https://news.ycombinator.com/item?id=12166332#12170616 https://news.ycombinator.com/item?id=12166332#12170616 Link reproduced for clarity: [1] http://thruglassxfer.com/ http://thruglassxfer.com/ [2] Demo of above: https://www.youtube.com/watch?v=2_8GlFdlb0Y https://www.youtube.com/watch?v=2_8GlFdlb0Y [3] Same idea, some hackable code: https://github.com/Neohapsis/QRCode-Video-Data-Exfiltration https://github.com/Neohapsis/QRCode-Video-Data-Exfiltration