Julian Assange knew what he was getting in to when he voluntarily got a security clearance, accessed information he wasn't authorized to access, and then leaked that information to the entire planet in violation of his security clearance. The leaks accomplished nothing of concrete positive value. He was perfectly free to leave government work and become a political activist without leaking classified information.

What? Julien Assange never received a clearance, he was simply the publisher.

Oh my bad, I mistook that for Edward Snowden.