If no one's been hurt, and the US has long upheld the need for law breaking when the law is unjust (the unlawful action of a black woman sitting in the white section of the bus) then I don't understand why his asking for a fair trial where established cases of just law breaking are brought up is contentious.
EDIT: I should clarify since I think there might be some confusion- I'm not saying that Snowden broke no laws. I'm saying I don't understand why his law breaking is contentious, given we have cases in the past of people breaking laws for just purposes that are generally accepted as just behavior. If Snowden wishes to make that argument, why are people scandalized about him wanting to go on a fair trial about it?