 | Most people don't realize how much information
they give out about themselves, especially their location. For example, you probably own a mobile phone. Every phone
on the planet has something called an ESN (electronic serial number.)
This is a unique ID that allows the cell towers to direct calls to
you. When you enter a cellular phone "cell" your phone transmits the
ESN to the network. When somebody calls you the network
routes the call to the cell tower closest to you, which broadcasts a,
"Hey, Wake UP!" message to your phone. Your cell-phone knows the call is for
you, (as opposed to the hundreds of other calls currently going on,)
because the network broadcasts your ESN. Your phone hears
it's own ESN and responds, "OK! I'm here!" Then your call is routed.
So, even when your phone is not in use the
phone is still broadcasting it's ESN all over the place. Thus, if the
government wants to know where you've been, it just asks the phone
company where your cell phone has been all day. In major metropolitan
areas, you can locate a cell phone user within about 100 meters. |
How about your computer? When you connect to a wireless network, your
network card identifies the SSID of the network. For most home users,
this is called "Linksys" or some other default-name. However, if you
work for FooBar, perhaps your system connects to FooNet. Then, when
you take your laptop computer from FooBar to Starbucks and try to connect to their
wireless Access Point (AP), your computer has no idea where it is. It
starts sending beacon messages to the last known AP, such as FooNet.
"Hellooo....? FooNet? Are you there?" Anybody who may be
eavesdropping on wireless signals knows that somebody is asking for
FooNet. If they can figure out that's you, they know where you've recently
been.
If
you are eavesdropping on wireless access points and you hear and SSID
that you don't recognize, you can look it up on sites like this: wigle.net. Even if you're not registered, you can zoom in on a map and check things out. Try zooming in on the Browsable Map O' The World.
Things to think about. As wireless devices become more
prevalent, we have to think about privacy and just how much information
we are leaking to the world.
The following paper is quite interesting: Can Ferris Bueller Still Have His Day Off?
Also, if you have an hour to spare, this video is VERY interesting:
http://video.google.com/videoplay?docid=-2160824376898701015 |