Apple: We 'must have' comprehensive user location data on you

Security researchers unveiled this week that Apple's iPhone was actively logging the whereabouts of users, storing location data into an easily assessible file on the device.
But it's not just iPhones that are keeping track of their users.
Apple's iPhone 3G, iPhone 3GS, the iPhone 4, and iPad models are also keeping track of consumers whereabouts. Mac computers running Snow Leopard and even Windows computers running Safari 5 are being watched.
The question is why?