The "quote" in question is that of a lawyer citing a previous ruling (they do that a lot) to counter a specific allegation:
“a person has no legitimate expectation of privacy in information he voluntarily turns over tothird parties.” Smith v. Maryland, 442 U.S. 735, 743-44 (1979).
The whole case is built on trying to make physical mail (snail mail) analogies applicable to email, they are accusing Google of "reading" emails when it's computers "parsing" text. That particular part of the motion is in response to the argument that non-Gmail users class action is valid since they didn't agree to the TOS. Google counters that "automated processing" is part of webmail.
Link to relevant page: http://www.scribd.com/doc/160041493/Google-Motion-061313#pag...
It's either the author have never seen a court briefing before or he’s just pushing an agenda.
The case is about Gmail "scanning" emails to target ads, Google is arguing (rightly so) that machines parsing emails is not equivalent to "reading" it, and that "automated processes" are responsible for spam filtering, spell checking and other features.
The entire motion, read it and make you own conclusions: http://www.scribd.com/doc/160041493/Google-Motion-061313