There are a lot of people that just do not understand about GPS tracking of cell phones. A lot of people believe that just because a phone has GPS capability, that the phone can be tracked using GPS. That is simply not the case and here is why:
1. A GPS unit does not transmit anything to the GPS system. It simply receives signals from multiple satellites to allow it to calculate its current position. This it true for hand held GPS units, cell phones, TomToms and all other GPS capable devices.
2. For someone to be able to track a phone using GPS a few things need to take place first.
a) The phone must have the GPS activated. This may seem obvious, but a lot of people do not realize this. Some phones have GPS activated in the default setting - so check your phone if you are not sure.
b) The phone must store the locations after acquiring the GPS coordinates. Most phone do this automatically if the GPS function has been activated. Note: All iPhones and iPads appear to log your location to a file called "consolidated.db." This contains latitude-longitude coordinates along with a time-stamp. Technically these are not done using GPS, but by cell tower triangulation. This information does not leave your phone unless you have certain apps (see c)
c) Some type of location sharing application has to be activated for the phone to be able to be tracked. This means the phone either is connected via the internet or sends the coordinates through text messages to a certain location.
I will expand on c just a bit. There are a lot of apps that may not tell you that you are sharing your location. At least they do not tell you overtly. An few of these applications are: Family GPS Tracker, GPS Tracker (for Android), Google Latitude, There are several "stealth" programs that can be installed, but a lot of social networking apps reveal and store your location in servers not in your phone.
3. Getting the GPS information from cell companies takes a subpoena for private investigators, but that information may be available for a lot of phones nowadays.
Whatever you do - stay safe.