Apple responded in April 2011 to concerns in the marketplace about location data that enables a user to be tracked without their knowledge or without knowing such a mechanism existed in the iPhone:
http://www.apple.com/pr/library/2011/04/27location_qa.html
By 3rd May 2011 an early fix was suggested would be available pending the outcome of Beta tests. That the fix would deal with location backups to iTunes when Location Services was switched OFF.
On the 5th May the promised iOS patch to resolve the iPhone location tracking went live and reduced the size of the cache of information that had been backed up. Noticeable the cache file is now considerable smaller, however the size of the update to do that was over 650 megabytes.
Loss of evidence in the cache is one observation and another is with Location Services switched OFF on the handset this may impact on historical and current Cell Site Analysis investigations.