Under CALEA (not FISA) telecommunication carriers are not required to decrypt, or ensure that law enforcement personnel could decrypt, communications encrypted by the end user unless they (the carriers) provided the encryption capability and possess the key ("information necessary to decrypt"). (47 USC 1002 (b)(3)). If Apple provides the encryption and retains or has access to the keying information, it appears they might be required to assist law enforcement agencies in executing warrants for encrypted data, although they might not qualify as "carriers".
Biting the hand that feeds IT
