Google has most of my email because it has all of yours (2014)
Eben Moglen, law professor and founder of the Software Freedom Law Center, gave a talk on privacy that discussed exactly this. I believe it was in 2011.    I would urge you also to consider that privacy is an ecological rather
    than a transactional substance. This is a crucial distinction from what
    you are taught to believe by the people whose job it is to earn off you.
    
    Those who wish to earn off you want to define privacy as a thing you
    transact about with them, just the two of you. They offer you free email
    service, in response to which you let them read all the mail, and that’s
    that. It’s just a transaction between two parties. They offer you free
    web hosting for your social communications, in return for watching
    everybody look at everything. They assert that’s a transaction in which
    only the parties themselves are engaged.
    
    This is a convenient fraudulence. Another misdirection, misleading, and
    plain lying proposition. Because - as I suggested in the analytic
    definition of the components of privacy - privacy is always a relation
    among people. It is not transactional, an agreement between a listener
    or a spy or a peephole keeper and the person being spied on.
    
    If you accept this supposedly bilateral offer, to provide email service
    for you for free as long as it can all be read, then everybody who
    corresponds with you has been subjected to the bargain, which was
    supposedly bilateral in nature.

(Full transcript available at [0], video at [1].)Interestingly I see I'm not the first to quote this at length on HackerNews [2].[0] https://webcache.googleusercontent.com/search?q=cache:qflooj...[1] https://www.youtube.com/watch?v=lRs8ZPbHtos[2] https://news.ycombinator.com/item?id=6747916(Link-rot has eaten the original [0] URL, and archive.org is seemingly down, but I realise the irony in linking to Google's cached page, as well as their copy of the video.)