Bradley (now Chelsea) Manning, as you may recall, was convicted of (among other things) violating 18 U.S.C. § 793(e), which in relevant part provides,

Whoever having unauthorized possession of, access to, or control over any document, writing, code book, signal book, sketch, photograph, photographic negative, blueprint, plan, map, model, instrument, appliance, or note relating to the national defense, or information relating to the national defense which information the possessor has reason to believe could be used to the injury of the United States or to the advantage of any foreign nation, willfully communicates, delivers, transmits or causes to be communicated, delivered, or transmitted, or attempts to communicate, deliver, transmit or cause to be communicated, delivered, or transmitted the same to any person not entitled to receive it, or willfully retains the same and fails to deliver it to the officer or employee of the United States entitled to receive it;

Yesterday, the U.S. Army Court of Criminal Appeals upheld the conviction; here's an excerpt:

Appellant asserts 18 U.S.C. § 793(e) is unconstitutionally vague in that the term "relating to national defense" as applied to classified records is not sufficiently clear as to provide fair notice and invites arbitrary law enforcement. Appellant also asserts the statute is unconstitutionally overbroad in that it prohibits a substantial amount of protected speech. We disagree on both counts….

The phrase "information relating to the national defense" is not defined in 18 U.S.C. § 793(d). Nonetheless, courts have held that " 'national defense' had acquired a well-known meaning 'as a generic concept of broad connotations, referring to the military and naval establishments and the related activities of national preparedness.'"

… ["]The root of the vagueness doctrine is a rough idea of fairness. It is not a principle designed to convert into a constitutional dilemma the practical difficulties in drawing criminal statutes both general enough to take into account a variety of human conduct and sufficiently specific to provide fair warning that certain kinds of conduct are prohibited.["]

… We reject appellant's claim that the statute is too vague to provide fair notice of the criminal nature of disclosing classified documents. The facts of this case leave no question as to what constituted national defense information. Appellant's training and experience indicate, without any doubt, she was on notice and understood the nature of the information she was disclosing and how its disclosure could negatively affect national defense.

… Appellant [also] asserts her actions in disclosing classified information related to national security are protected by the First Amendment and that she did not have reason to know the records she disclosed could be used "to the injury of the United States or to the advantage of any foreign nation." We disagree. Appellant had no First Amendment right to make the disclosures—doing so not only violated the nondisclosure agreements she signed, but also jeopardized national security.

United States courts have repeatedly held that the First Amendment does not protect unauthorized disclosures of classified information…. In the face of a similar First Amendment challenge, the United States Court of Appeals for the Fourth Circuit, in U.S. v. Morison (4th Cir. 1988), upheld the Espionage Act convictions of an employee of the Naval Intelligence Support Center who had a Top Secret security clearance and had also signed a non-disclosure agreement. The accused unsuccessfully argued his conviction under the Espionage Act could not stand because he leaked the classified information to the press, rather than to a foreign power.

The Fourth Circuit stated: ["][T]hough he cannot point to anything in the legislative record which intimates that Congress intended to exempt 'leaks to the press,' as the defendant describes it, he argues that, unless such an exemption is read into these sections they will run afoul of the First Amendment. Actually we do not perceive any First Amendment rights to be implicated here …. It is a prosecution under a statute, of which the defendant, who, as an employee in the intelligence service of the military establishment, had been expressly noticed of his obligations … is being prosecuted for purloining from the intelligence files of the Navy national defense materials clearly marked as 'Intelligence Information' and 'Secret' and for transmitting that material to 'one not entitled to receive it' …. We do not think that the First Amendment offers asylum under those circumstances … merely because the transmittal was to a representative of the press.["]

Id. at 1068 (citing Branzburg v. Hayes (1972) ("It would be frivolous to assert—and no one does in these cases—that the First Amendment, in the interest of securing news or otherwise, confers a license on either the reporter or his news sources to violate valid criminal laws.")).

We squarely reject appellant's First Amendment challenge and firmly hold that a soldier who willfully communicates information relating to the national defense "is not entitled to invoke the First Amendment as a shield to immunize his act of thievery." …