There's two issues here;
1: Various US government departments may be doing something dodgy
2: Someone is leaking classified data to the wider population
Now, I've no opinion on the first one - I'm not a US citizen (though I class myself as a US sympathizer). If true, it's a thing for the citizens and the justice department. I hope the issue gets resolved, right prevails etc
But the second one is a security breach: the guy (whatever his intentions) has broken his contract with the company, and also the law. What documents get released to the wider public is not a matter for the individual - it's a matter for the owners of the data, according to the law.
And as someone who's hired staff in the past, I'd be less than impressed if someone admitted that he'd leaked data to the public because he thought it was the right thing to do. That's my call, not his. Or more likely my boss's. Or his boss's.