In their statement they outlined what kind of requests they have received. They also explained a bit about how your information is handled:
Apple further says that among those requests, the most common came “from police investigating robberies and other crimes, searching for missing children, trying to locate a patient with Alzheimer’s disease, or hoping to prevent a suicide.” The statement claims that when receiving such requests, Apple provides only the narrowest possible amount of information, and only if appropriate. The statement notes that Apple sometimes refuses to fulfill inconsistent or inaccurate requests.
Apple also outlines the kinds of data it does not provide to government agencies. FaceTime and iMessage messages, which are encrypted, cannot be provided to government agencies because Apple chooses not to retain that data. Location information, Maps searches, and Siri requests are never retained in personally identifiable form.