Since Van Eck phreaking tools exist which can read keystrokes and RAM states on specific machines from blocks away, and since no one talks about these tools, I am leaving this comment here.
What a bunch of nonsense. Reading out RAM states and keystrokes from one room over is already quite a feat, to read RAM states or keystrokes from 'blocks away' is science fiction and if it could be done would be news to me.
Yes, it is possible to recreate the contents of screens from quite far away, it is possible to piece together a lot of data from magnetic fields leaking from computers but this is not simple nor something that easily lends itself to longer distances.
In short, the reason nobody talks about those tools is because they don't exist.
From blocks away? Bullshit. Maybe from the next room using a CRT monitor. I'd love to see the study saying they're able to reliably get keystrokes or screen images from any significant distance.
Yes, it is possible to recreate the contents of screens from quite far away, it is possible to piece together a lot of data from magnetic fields leaking from computers but this is not simple nor something that easily lends itself to longer distances.
In short, the reason nobody talks about those tools is because they don't exist.