> damage to US national security isn't against the law.
Consult a lawyer before you try something like this, but AFAIK the Espionage Act of 1917 (which SCOTUS has affirmed does not infringe the 1st Ammendment) does probably apply to this kind of thing. In this particular case, it will probably be difficult to make the charge stick; the best coverage I've seen of this is here:
http://www.washingtonpost.com/wp-dyn/content/article/2010/12/03/AR2010120303267.html
But that doesn't mean it isn't illegal, and it certainly doesn't mean that people haven't been convicted and imprisoned for violating that law.
Obvious further reading: http://en.wikipedia.org/wiki/Espionage_Act_of_1917
/jordan