If he was tried, couldn't he (at least theoretically) be acquitted by the jury? Honest question; I don't know that much about the U.S. judicial system, but I'm aware of the concept of jury nullification.
(Not that I'm too keen on the possibility that the U.S. government would grant him the chance of a fair trial...)
Yes, juries in the USA can render any verdict they choose in criminal trials. Jurors cannot legally be punished for their verdicts, judges cannot direct verdicts in criminal trials, and acquittals cannot be appealed.
I think courts should be legally obliged to make jurors aware of that fact. Overall, I'm not a huge fan of trial by jury, but the idea that an unjust law (as felt by the general public) can be defeated like that certainly appeals to me.
(I'm not trying to make a point about Snowden's particular case, just speaking in general.)
It's in fact the opposite: the jury is explicitly told to judge the case, not the law, and mentioning nullification as a juror will certainly get you thrown out during the selection process, and I've even heard of cases which were sent to mistrial when the jury's intent was revealed. The best way to successfully nullify is to pretend that you've never heard of such a thing.
I do hope there's a demographic shift here. Facing heavy-handed laws regarding drugs and such, web-savvy young people seem to be slowly catching on about tactics like nullification, not talking to police, etc.
(Not that I'm too keen on the possibility that the U.S. government would grant him the chance of a fair trial...)