[masraum]

Originally Posted by jyl

Can I set up an Apple Airport Extreme so that it does not broadcast any information?

Never mind. I can indeed. I guess it can still bf snooped but probably a run of the mill smartphone won't.

So, next time I buy a new router, I will set to not broadcast, and see if Google knows where it is.

Not broadcasting the SSID is not a security measure and could actually prove to be a pain. The RFC requires the SSID broadcast. Some devices don't care, but other devices will be really unhappy with that configuration.

My phone will see wifi signals that have SSID broadcast disabled. Besides, a MAC address (which cannot be disabled) is a better tool to use than the SSID anyway.

By disabling the SSID broadcast, you aren't really helping yourself.

Just a somewhat related tidbit.

Houston TranStar and Bluetooth Traffic Monitoring

Houston TranStar uses various technologies to measure the average speed and travel time of vehicles as they travel along a roadway. Information collected from these technologies is the source for providing travelers with traffic information in various formats including:

* The color-coded speed map on the Houston TranStar Website.
* Travel time messages on roadside message signs.
* Information used by radio and television media for reporting traffic conditions.

The primary source for measuring speeds and travel times in the Houston region has been from the use of toll tag information. Recently, the Houston TranStar partners have been implementing traffic sensors that make use of Anonymous Wireless Address Matching (AWAM) to measure speeds and travel times along roadways.
Anonymous Wireless Address Matching Using Bluetooth

Houston TranStar's AWAM System detects vehicles equipped with enabled Bluetooth networking devices, including cellular phones, mobile GPS systems, telephone headsets, and in-vehicle navigation and hands-free systems.
AWAM

Every Bluetooth device has an electronic address, known as a MAC address, used to identify it to other network devices. Each roadside AWAM reader senses these addresses emitted by enabled devices as they pass the reader station.

For real-time applications, the AWAM reader then transmits the time and location of the device to the AWAM host processing system at Houston TranStar. As probes are detected at successive AWAM readers, the host system merges travel time readings to calculate average travel times and speeds for a roadway segment.
A Note About Privacy

The MAC addresses read by AWAM are not directly associated with a specific user and do not contain any personal data or information that could be used to identify or "track" an individual's whereabouts. In addition, all addresses collected by AWAM are anonymized through encryption immediately upon receipt. Users who have privacy concerns are also able to turn off the Bluetooth discovery function of their device which prevents it from being read by AWAM at all.