@Eorl,
Governments seem to love to find excuses to increased their ability to spy on us in mass.
An example of that is the need to be able to located cell phones for 911 reasons that is now used far more often to track citizens either in real time or even going back into the past by law enforcements and other government agencies.
I can see little reason other then mass spying for cell phone providers to keep detail pinging records going back weeks or months.
All of us who carry cell phones are in fact carrying location beacons for the government.