I saw this on "BusinessInsider" and assumed that someone it was someone playing with them. But no, it appears that Snowden, as well as being a better hacker than Lisbeth Salander he is also Jason Bourne.
In order to defend his claim that even though he took highly classified information, some of which would be damaging to the US, he won't divulge it because "...I cannot be coerced into revealing that information, even under torture."
So here is a guy that asserts that "... I have not provided any information that would harm our people - agent or not - and I have no intention to do so." Yet information he provided to both the Guardian and the Washington Post were deemed by those organizations to be too sensitive for them to publish. He has also apparently created "insurance packages" that will release all this information if "he is harmed in any way." So I guess he didn't intend to create those packages, it was an accident.
Senator Humphrey prefaced his letter with "Provided you have not leaked information that would put in harms way any intelligence agent, ...", and the good former Senator can feel comfortable because one of Snowden's hidden talents is being immune to torture.