Hi, just thought I'd butt in
It's a very interesting subject, and I completely understand your interest in this subject Koroth. Also, the rest of you, its refreshing to see people discussing things, and contributing in a constructive manner.
About EM emissions. Although the EMI from CRT monitors is terribly 'muddled' I have seen methods for 'capturing/decoding' them. The advent of the computer age, with its ability to execute horrendously complicated algorithms, can do so much. Its not just CRT monitors that can be 'decoded'. Virtually any data transfer using significant current can be intercepted. As I'm sure you all know.
But, as someone said, LCD monitors emit far less EMI than a standard CRT monitor (the nature of CRT, with its HV, high power magnetism(cannot be shieled) and its 'old' approach to display, is just begging to be picked up). Also, as you all know, EMI falls off to the square, and probably to the cube considering these devices are placed in buildings with fading channels, walls, people, etc.. to reflect/absorb radiation. There must come a point where the EMI amplitude is so low that it cannot be picked up effectively, and because we live in a 'sea' of EM radiation (radio, TV, GSM, ELF etc..) the noise floor is terribly high, drowning out these emissions.
My point, is that although I'm sure with clever electronics, the EMI from many different devices could be picked up, and it is a security risk. However, its less than it was a few years ago, because of the above reasons. If people are paranoid about people viewing text on your screen, why not learn another language? I bet the little hackers won't expect that
I vaguely remember the BBC prog (in the UK here) and they were very scared, even though the range was in the order of a few cm. If you can pickup things 50m away, from your equipment - get different equipment. For EMI to extend that range, and sitll be above the noise floor, the equipment is obviously using waaay too much power, not well sheiled and probably not doing yourself much good either. After all, its well documented that low to medium EMI has a greater negative effect on biological systems than high-power EMI.
Finally, we are starting to see some 'negative' effects from our own 'wonderful technology'. Of course people will use it for crime, as far as I'm concerned, if something is designed so badly that it kicks out EMI, or if someone buys equipment that does so, then they shouldn't complain about having data stolen. (not that anyone here was doing so..)
My pointless opinions...
BuriedCode.
1 in 6 billion...meaningless, yet completely unique.