In my opinion it would probably be using Qubes certified hardware with Qubes on it and then routing everything through whonix VM.
Curious to know if anyone has anything else that is more secure than Qubes - I mean like does anyone know what darknet vendors use opsec wise?
Also I heard Snowden used Tails OS when blowing the whistle - so perhaps using tails would be up there.
The creativity of research students shouldnt be underestimated lol, they have found ways to transmit data to cameras, to microphones (inaudible to us), and also by using coil whine in power supplies, all by modulation.
There is the caveat that these usually require the computer to be compromised first though, if it is airgapped