There is a federal statute that makes it a crime for public employees who have been granted access to classified information to reveal that information to persons who are unauthorized to receive it. From a simple technical legal standpoint, there is absolutely no question that Snowden violated the law. From that standpoint, if he is tried, he will be convicted, and he is in fact a criminal. Whether one admires what he did is another question, but it does not have anything to do with whether what he did was unlawful.
Why I think he deserves punishment, he said it actually himself. He said, “I’m just an ordinary guy.” He is just an “ordinary guy” with absolutely no expertise in public policy, in the law, in national security. He is a techie. He made the decision on his own, without any authorization, without any approval by the American people, to reveal classified information about which he had absolutely no expertise in terms of the danger to the nation, the value of the information to national security. That was a completely irresponsible and dangerous thing to do. Whether we think it was a positive thing in the long run is a separate question, but it was clearly criminal.