It's not what he did it's what he knows and where he is (enemy territory). He does not have to willfully give out the information. They can take it via torture or stage an accident.
Nobody has shown that he has given any sensitive information to include sources and methods to anyone. Just having the knowledge in your head or even on a flash drive (which I doubt) does not mean you are giving it out regardless of which country you are in. Again, the fact that he talks about domestic spying on communications media is not secret or sensitive in any way; it has been common knowledge for many years. He also does not have complete knowledge of the entire set of operations because he, like many others, had compartmented clearance specific to his job. He knows only the pieces he had a need to know and very few ever have complete knowlege or access to that knowledge for any compartmented program.
Panetta on the other hand gave over operational information that put operators in jeopardy and which revealed key aspects of some operations.
I see the uproar and enhancement of this toad to be a useful tool to focus attention away from other more important scandals this administration is responsible for. It is yet to be shown that he has truly released any really sensitive information despite the bloviation of the higher ups. Let’s wait and see. There’s nothing that can be done right now with Snowden one way or the other and efforts are better spent going after the IRS and Dept of Justice for their crimes against the U.S.