Apple 'privacy czars' grapple with internal conflicts over user data

"Key principles include keeping customer data on their devices - rather than in the cloud, on Apple servers - and isolating various types of data so they cannot be united to form profiles of customers.

Such privacy guidelines can cut against engineers' instincts to "collect all the data, because sometime down the road it may be useful," said Albert Gidari, director of privacy at Stanford University's Center for Internet and Society."