http://thelede.blogs.nytimes.com/2011/10/12/u-s-accuses-virginia-man-of-espionage-at-syria-protests/
The precedent of accusing an American for “spying” because he gathered names and email addresses of people opposing the Syrian government and sending them to Syria would be a dangerous precedent. Even if true, he was not gathering secret information about any aspect of the United States government and its operations.
There are many governments that routinely collect information about their expats and what they are doing after they leave their homeland, or people they believe might be acting against the interests of that country, but that is not a “espionage” against the country where the activity occurred.
The act of obtaining, delivering, transmitting, communicating, or receiving information about the national defense with an intent, or reason to believe, that the information may be used to the injury of the United States or to the advantage of any foreign nation. Espionage is a violation of 18 United States Code 792-798 and Article 106, Uniform Code ofMilitary Justice. See also counterintelligence.
Dictionary of Military and Associated Terms. US Department of Defense 2005.