"Data Exfiltration from Speakerless Air-Gapped fanless Computers with SSDs via Software-Driven Variations in Overall System Power Consumption."

I remember reading, in a computer magazine about 15 years ago about a technology, or else an area of research that claimed to do just this. To infer what is being typed on-screen from subtle variations in radiation emitted from the monitors. Apparently some degree of success was possible even outside a building. It probably related more to the CRTs of the day, and the less noisy UIs.

Van Eck Phreaking: https://en.wikipedia.org/wiki/Van_Eck_phreaking

"It probably related more to the CRTs of the day, and the less noisy UIs."

I imagine it's easier with stronger emissions (e.g. CRTs), but also still relevant with EM emitting from modern displays

"Data Exfiltration from Displayless Speakerless Air-Gapped Fanless Computers with SSDs via Subtle High Frequency Modification of USB Voltages". AKA your mouse wire is your new antenna.

Ah, nice, that's elegant.