But even if Google isn't obligated to lie, it might still be lying.
Maybe Google is lying, not because it's obligated to by the law, but because it's immune from the consequences of lying and the government is leaning on them in other ways.
Maybe Google is afraid of the backlash that will follow if they don't lie.
Maybe Google has carefully written their denials to be technically true, but still hide the real extent of the data they're giving to the NSA. This was my original point, which you completely ignored.
And yes, maybe Google is being completely forthright.
We have very little information, and information we do have may be wrong. Given that, I don't think it's wise to conclude that transmitting email over an encrypted channel is enough to keep out of the hands of the NSA.
> NSA doesn't have Google's private key.
And socks come in pairs.
But I'd be very reluctant to conclude that the NSA doesn't have clear-text for the vast majority of email that gets sent.
Google and other email providers have denied giving the NSA access to their servers, but if you think about it, that would be a lousy way to share data with the NSA, from a purely technical point of view. A company like Google is going to be constantly evolving their infrastructure. Giving the NSA direct access to the servers hampers that, because they'd have to break compatibility with whatever client software the NSA is using. It'd be easier to just send copies of all email that moves in and out of their system to the NSA and let them sort out how to process it. That would be more convenient for the NSA too.
Beyond that, all the denials issued by Google, Facebook et al mention that they do provide the government with information as required by law. We know that there are secret laws at work here, and if the law requires companies hand over everything, then that's what they're doing. The may even be required to lie about it. They're definitely absolved of any legal liability for doing so. I don't doubt that internet companies try to protect their user' privacy as much as they can, but that may amount to "not at all" where the U.S government is concerned.