Does the Stored Communications Act Protect an Email's Subject Line From Disclosure?

In other words, is the subject line considered "content" which the SCA says a service provider cannot disclose to a third party? Optiver Australia Pty. Ltd. & Anor. v. Tibra Trading Pty. Ltd. & Ors., 2013 WL 256771 (N.D.Cal., January 23, 2013)

Plaintiff served Google with a subpoena seeking, among other things, the subject line of emails associated with certain of defendant's Gmail accounts. Defendant moved to quash the subpoena inasmuch as it sought the email subject lines. The court granted the motion to quash.

The Stored Communications Act at 18 U.S.C. 2702(a) states that, subject to certain exceptions that do not apply here, email providers may not knowingly divulge to any third party the contents of an electronic communication.

The court found that a subject line serves to convey a message about the body of the email and the substance of the communication. Since a message's subject line is "nothing less than a pithy summary of the message's content," the court found that the supboena seeking production of email subject lines ran afoul of the SCA.