[UFO Chicago] [declan@well.com: FC: FBI releases advisory about 802.11-spotting "wardriving"]

[Vitaly McLain]

| > Did anyone here listen in on converstations using their FM
| > radio?  I seem to have dim memories of people using those
| > old analogue radios to get a few more Hz above or below the
| > FM band to listen to various radio converstations.  In
| > cases like that, you can't (cheaply, where "cheap"=="no
| > cost") block other people from receiving your
| > transmissions.


I am not sure it is possible with an FM radio, although people have done
this with TVs. If you have an antenna and live near a cell tower, tunning to
certain channels (I believe around channel 83) and tunning the antenna can
cause the TV to pick up cell phone conversations.

It's actually not that hard to pick up a lot of conversations. Due to FCC
regulations, frequency scanners sold at stores block the 800Mhz (I believe)
range to prevent people from snooping on cell phones. Scanners most also
made "difficult to modify" to pick up that range. "Pre-block" and
European/Japanese unblocked scanners pop up on eBay and similiar places
every so often.

I suppose I should also mention cordless phones. Due to various wiretap
laws, it is illegal to listen in on conversations -- but no law says
scanners must block the various ranges cordless phones use. Many of the
older phones can be found around 43Mhz and many of the newer ones around
900Mhz. Most scanners don't go up to the 2.4Ghz range, so users of those
phones are pretty safe. Some phones implement various technology to thwart
snoops, but many don't.

As an experiment: I have a RadioShack Pro-89 handheld scanner with a small
telescoping whip antenna sitting next to me. I live in a town house, so I
have neighbors, but not as much as an apartment. For the sake of
experimentation, let's see what's around 900Mhz now:

903.6375Mhz -- Woman's voice, bearly picking it up but audible.
906.somethingMhz (lost it) -- Children's music; most likely a baby monitor
Scan again: 902.2125Mhz -- Clear conversation

(I did that for the sake of experimentation, and didn't listen to any of the
conversation, so don't worry, no one's privacy was intruded for more than 2
seconds.)

Anyway, that was probably too much info, I'll go back to lurking now ;)

- Vitaly