<i>At least some phones running Google's Android OS</i><p>Android is a <i>dream</i> for someone like me (forensic analyst). It is easy to get data off, and is chock full of all sorts of cached information. iPhone is more difficult, and can sometimes be very hit and miss in what you can get off it.<p>I've used pretty much all of the tools listed on that page, and none are as magical as they claim. One of the best is .XRY, which is my preference because for a lot of phones you can use it to extract a raw memory dump and analyse it more carefully/deeply.<p>The key thing to know here is that <i>all</i> phones cache location information like this in some form. Older phones used to only cache a little bit, but usually enough to recover some previous cell sites. Modern phones, with more location features, more memory and more advances OS's, just store more of this information.<p>IMO it's not so much that LE have been keeping it deliberately quiet. I mean, I for one figured it was fairly obvious. The story here is, IMO, it being sent back to Apple/Google etc. Not that the data is cached.
This is quite common, years ago I was working as a security consultant to a police department and this was before EFF made it public - <a href="http://w2.eff.org/Privacy/printers/docucolor/" rel="nofollow">http://w2.eff.org/Privacy/printers/docucolor/</a> they were actually arresting people based on tracking printer serials in money counterfeiting cases.
This particular topic has been discussed to death lately. It's really not that big of a deal. Apple is doing this to aid in the phone being able to Triangulate it's position in relation to cell towers (when gps is unavailable).<p>Also, the phone is NOT constantly tracking your location. It only logs a new location (a) when you launch a location-aware app, e.g. Facebook, Maps etc. And (b) when you have never been to that location before.<p>It does not log the amount of times you have visited the location.<p>I suspect Apple is planning to do something cool with this Data, because of the way it is synced across Computer and Phone. Keep in mind however, the Data cannot be used to Track you constantly, only to see where you have been in the past, but, the log will never update to show that you visited a certain location more than once.
Hope this helps!