Fifty Plus (50+) - Does this make sense?

A friend and I are having a discussion about this. I was reading Craig's List, and I saw a listing for a stolen garmin. This made no sense to me... if they can track a vehicle when their keys are locked in the car or they're lost in the mountains, and if they can track all of us on our cell phones, then they should* be able to track a tracking* device.

My friend accepts the incongruity a lot more easily and sent me this, from a GPS forum:

Question: I had a Garmin Nuvi 350 which was stolen from my vehicle. I was wondering if there was any way I could try and track the device? Like some sort of software I could download and use on my computer ... or even an addition to my new Garmin Nuvi 660. I have the box and serial number and other unique numbers that were found on the back of the navigation device.

Answer: GPS units only receive tracking data. It is not possible to track a given unit. You should report the theft to Garmin, however, as I believe they maintain a database of stolen units, and may be able to track attempted updates of a specific serial #.

Think of a GPS as a radio receiver with built in computer that tells you where you are on the screen. It does not transmit any information so can't be tracked. Cell phones transmit their location so they can be tracked.
About the only thing the owner could do would be to report the serial numbers to Garmin and the local authorities, hoping that it might turn up somewhere down the line, either as a repair item or in a local pawn shop, etc. Even publish the serial number and put on a bulletin board in the local gyms, YMCA's bike shops, etc. You never know if it will turn up and some honest person will report it.

But, it has to ping a satelite or something....

What about those commercials where you get into an accident and they know where you are because of your car system... is that something entirely different?

But, it has to ping a satelite or something....

What about those commercials where you get into an accident and they know where you are because of your car system... is that something entirely different?

I believe the in-car systems use cellular technology in addition to the GPS. I have Onstar in my van but never renewed the service after the first year which was free.
http://www.onstar.com/us_english/jsp/explore/onstar_basics/technology.jsp

But, it has to ping a satelite or something....No, it doesn't. It listens to the satellites, and figures out where it is based on the signals it receives and their timing.

http://electronics.howstuffworks.com/gps.htm

http://en.wikipedia.org/wiki/Global_Positioning_System

Oh, cool! Very interesting. GPS works totally different than I had imagined it. Thanks!

(apolgies to Yen)