Interesting. As they are not Gmail users, they may have something there.
In regular mail, though, once a letter is delivered to a recipient, it belongs to the recipient, and, in this case, the recipients agreed to Google's TOS. Whether or not they actually
read the TOS is another matter.
I wonder whether the NSA will file
amicus briefs.
In related news, interesting (and opinionated--be forewarned) vid on "non-exclusive licenses" and the NSA:
http://www.youtube.com/watch?v=vEE8ptrDqhQ
