When I was a 21/22 year old enlisted man in the US Army, I held a "secret" clearance, for the nature of my work.
I was trained that East German/Soviets might attempt to befriend me, for the purpose of finding out about our troop strength, etc.
Supposedly one way it worked, was GIs drinking downtown, and having loose lips. I spoke pretty fluent German, and a couple of Germans thought I might be CIA or something.
Of all of the subjects regarding rules, the aspect of confidentiality-national security was pounded home, as REALLY serious.
It would have been unanimous among my fellow soldiers, that we keep secrets, secret. Unlike these days with Snowdon & Assaunge as heros to some.
In the case of Clinton, it is astonishing to see her go unpunished. There is a standard in law, of what you know or SHOULD KNOW.
Ignorance of the law is not a defense. And these are laws, not suggestions. National security used to be a serious subject.