In the Business Insider article about GMail privacy there is a quote from Eric Schmidt from a 2009 interview:
"If you have something that you don't want anyone to know, maybe you shouldn't be doing it in the first place," Schmidt said. "But if you really need that kind of privacy, the reality is that search engines, including Google, do retain this information for some time. And ... we're all subject, in the United States, to the Patriot Act, and it is possible that that information could be made available to the authorities."
Since then this quote has been picked apart, but if you were wondering, here are some of the things that “maybe you shouldn’t be doing”, but “really need that kind of privacy”: being gay, in an interracial relationship, and/or ingesting marijuana.
I doubt that anyone at Google would say they think those civil or cognitive rights shouldn’t be protected. Nor do I think anyone would go on record explaining how the ubiquitous nature of GMail is a dangerous tool for coordinating a movement, if it would run contrary to the current (at any time) government regime.
A reminder: Mailpile wants to make mail encryption easier.