I have a Garmin Mode S transponder.  I got used to being tracked by Flightaware and told people they could track my progress there -- up until recently (a few months ago?) Flightaware tracked me whenever I was squawking a unique code (not 1200).  But recently, they seem to track only IFR; seems like they've dropped VFR flight following.  I compared notes with some of the folks at the Placerville Fly In, and they'd observed the same thing.

On Jul 22, 2013, at 2:28 PM, Jay Phillips wrote:

I've had ADS-B out in my Legacy for several years and in my IV-P since the
first of the year. Never happened to me. I mostly fly VFR with flight
following so maybe it's an IFR thing?

The car thing is already happening. Article in the news last week says that
using cameras and license plate recognition various agencies are building
databases of where/when your car has been. If you have OnStar or something
similar your car is already being tracked.

Jay Phillips