[citation][nom]q3r2q3rj1kla[/nom]physically seperated networks with NO wireless transmission/access are not completely secure from a remote security attack either.. You might say that cant be since there is no access point. However you dont need an access point to read data. You can read any electronic signal at a distance with the right equipment(its not even that expensive). As long as electricity flows through a wire, any wire, you can detect the signal. With the right equipment i could park my car out front of your house and display the contents of your monitor on my monitor without having to break into your system. You just passively read the EM signal that a monitor makes as it paints a picture, then paint it back out on your monitor. Sure its not the same thing as full network access, but in terms of security, just being able to read your data is plenty to breach you.That said...yes a physically separated network is leaps and bounds more secure then anything else.[/citation]
You got this from a Tom Clancy book or some other way that has nothing to do with reality. If you think you can pick up a MHZ band signal at any distance you don't know anything about electronics or how and why the FCC operates. Hint: your first problem is noise. Technically, I'm sure it can be done with the ideal laboratory setup, conditions, and a lot of tuning in a lead lined room. But in reality if the government wants to know what is on your computer or what you are doing with it they will just monitor your internet connection or for high profile cases sneak into your house and install a transmitter/keylogger/rootkit of some kind into it.
Its also only getting worse with higher resolution monitors that are digital. We will see the gun in Eraser before we see anyone wasting their time with this crazy idea. But then again if it is the government I can see them trying to design something that has absolutely positively no practical usability. Maybe it was part of the stimulus.
The only honestly realistic (and well known) way to get around an airwall is to compromise some part of the organic material in-betwixt the networks.