If you have an iPhone or iPad with an operating system installed after June 2010, your electronic connection tool to the world is tracking your movements constantly and recording this data.
The fact that these devices include GPS (global positioning system) or cellphone tower tracking should have been fairly obvious because many apps such as those showing you nearby stores could only work if the device “knows” where you are.
What is relatively new is the discovery (or at least the reporting) that this data is backed up each time you “sync” the device.
Currently the only way known to stop this is to encrypt backup data which doesn’t actually stop the recording, just makes it a bit more difficult for someone else to dig it out of your computer or hand-held device. (Not all that difficult since many people still use the password “password” or other easily guessed words or numbers.)
There may be a way to stop the devices from recording the location data initially but then many apps wouldn’t work so why spend the money on the device? Also, how do you really know there isn’t some other hidden, perhaps Apple encrypted, backup.
Besides the possible downside of this tracking, such as the police (or worse yet, your significant other) finding where you were at any time; it is just possible this information could help establish an alibi in either instance or help locate you in an emergency by finding where you often travel.
Here is a link to the bloglog announcing the backup of position data,
http://radar.oreilly.com/2011/04/apple-location-tracking.html
This link is to the original announcement of the data collection (in French)
http://www.courbis.fr/Localisation-iPhone-votre.html