http://www.nytimes.com/2004/12/12/ma...er=rssuserland

"Keyboards are a bit like drums: the keys rest atop a plastic plate;
different areas of the plate yield different sounds when struck. The human
ear can't tell the difference, but if the sounds are recorded and processed
by a highly sophisticated computer program, the computer can, with a little
bit of practice, learn to translate the sounds of keystrokes into the
appropriate letters and symbols.
This means that firewalls and passwords will amount to nothing if someone
manages to bug a room and record the cacophony of keystrokes."

"Mickey Segal" <ignored@example.com> wrote in message
news:OVLjLaJ4EHA.1260@TK2MSFTNGP12.phx.gbl...
> http://www.nytimes.com/2004/12/12/ma...er=rssuserland
>
> "Keyboards are a bit like drums: the keys rest atop a plastic
> plate; different areas of the plate yield different sounds when
> struck. The human ear can't tell the difference, but if the
> sounds are recorded and processed by a highly sophisticated
> computer program, the computer can, with a little bit of
> practice, learn to translate the sounds of keystrokes into the
> appropriate letters and symbols.
> This means that firewalls and passwords will amount to nothing
> if someone manages to bug a room and record the cacophony of
> keystrokes."
>
>

I was told by a friend that there also existed a technology
which could translate what shows up on your monitor by the
signals that a CRT makes, but that this technology doesn't work
for LCDs. I was told this years ago, so who knows what they
have now.
http://www.ghu.ca/Docs/eaves.htm
About 3/4 of the way down, the Electro-Magnetic Radiation
section

--
TCPW
The Miniature Mage