There’s no evidence that it’s being transmitted beyond your device and any machines you sync it with; however iPhone records your location second by second by triangulating your position from nearest mobile phone towers. The information is stored in an easy-to-hack place which leaves you open to all sorts of privacy issues and malicious attacks.
have created the iPhoneTracker app to highlight the incredible detail this app records. Interesting & intimidating isn't my favourite combination....
Check out more details at the iPhoneTracker app homepage.