content: Well they're still using Google's emailing system and this is part of their TOS although Google is breaking wire tapping laws this is not the first time they've been sued by students for this very thing. It happened in 2013. As a matter of fact even Twitter scans private messages, they all do this for the sake of advertising revenue... Microsoft was behind the wave on this as ads were not their core business but that seems to be changing with Windows 10, Bing and their future freeware. The best way to avoid this is by self-hosting and running a private email server (just ask Hillary) but then when you email someone with a Google email your email would be scanned anyways...