I don't expect them to say no. That's why I don't expect them to imply that they would or suggest that they never have.
And, if you keep your headquarters in Cupertino, quite possibly from US authorities as well (see the currently in-progress Microsoft case about access to servers in Ireland).
It's been "fun" to read Jewel vs. NSA proceedings, press statements, and officials' statements about these issues because of the extent to which they play word games to technically not lie according to specific (re)definition of words.
Even if you are root it's no guarantee, thank you rootkits :/
As with all things security, sometimes it comes down to trust and legal protections.
You could still NSL a backdoor, but if the service is open source at least there's a chance of the code being audited.
Without a trust the only thing that comes close is an in person P2P pairing ceremony.
Key management might work in an enterprise setting with a central authority, but making sure your friend's public key isn't swapped with the government's is pretty hard if you don't trust the cloud provider, telecom, or intermediate infrastructure.
Yes, that's true. But if you run an email service that's based in Cupertino, what do you do when served with a lawful search warrant or wiretap order? Say "no," and be found in contempt of court and have all your servers carted away by some men in black so they can find the file they're looking for?
There are a few ways around this. One is not to permanently store warrant-worthy user data (Snapchat, Wickr, etc.). Another is end-to-end encryption (original version of Hushmail), though key distribution and UX become problems. A third is to move your servers to Switzerland, though then you get served with process from the Swiss authorities instead of FBIDHSDEAetc.
Apple has taken none of these steps. Assume our hypothetical Cupertino-based email service has not either. What do you do when the Feds show up with a lawful order?