There comes a point where privacy and security are simply not possible. If
you use a PC, no matter what software you have installed you are vulnerable.
And despite all the hooha about back doors, hidden spyware, etc, all ISP's
(certainly in the UK and therefore almost certainly in all "Western developed
nations") records are kept of all you do, see and say. Even the very keyboard
strokes you make are detectable, even if you are not online at the time.
Which is of course not to say they are listening, just that if theyt want to,
you have zero chance of avoiding detection.
The following excerpt is taken from a pdf published in 2009, address at the
bottom.
Computer keyboards are often used to transmit confidential data such as
passwords. Since they contain electronic components, keyboards eventually
emit electro-magnetic waves. These emanations could reveal sensitive
information such as keystrokes. The technique generally used to detect
compromising emanations is based on a wide-band receiver, tuned on a specific
frequency. However, this method may not be optimal since a significant amount
of information is lost during the signal acquisition. Our approach is to
acquire the raw signal directly from the antenna and to process the entire
captured electromagnetic spectrum. Thanks to this method, we detected four
different kinds of compromising
electromagnetic emanations generated by wired and wireless keyboards. These
emissions lead to a full or a partial
recovery of the keystrokes. We implemented these side-channel attacks and our
best practical attack fully recovered 95% of the keystrokes of a PS/2
keyboard at a distance up to 20 meters, even through walls. We tested 12
different keyboard models bought between 2001 and 2008 (PS/2, USB, wireless
and laptop). They are all vulnerable to at least one of the four attacks. We
conclude that most of modern computer keyboards generate compromising
emanations (mainly because of the manufacturer cost pressures in the design).
Hence, they are not safe to transmit confidential information.
Taken from www.usenix.org/event/sec09/tech/full_papers/vuagnoux.pdf
