Jews were legally killed as far as the Nazis were concerned.
Just become something is legal - in this case a wrong assertion because spying on citizens is against the constitution so it is illegal - does not mean that it complies with Human Rights.
The fact is that Snowden had the opportunity to quit when he found out what his work was going to entail or what his work was being applied to if he didn't approve. He continued to work and collect a paycheck. He knew he was breaking the law.
As much whining goes on here at HN about the lack of personal responsibility it's ironic that there's a ton of people so willing to not face the facts about the situation.