Unfortunately, Snowden is in the wrong and so are many ill-informed people that blindly support him. They know not the clearance or classification systems, and would rather wish that everything was in the open - even if that meant more harm than what Snowden that already has caused(which is not a null quantity) to the US and its citizens. It doesn't matter who says it.
If anything, the NSA has been more transparent in decades than Snowden has been during this ongoing unmitigated information security disaster. We can openly check what the NSA has done, but we have to take Snowden at his untrustable word that he hasn't already given information to Russia & China to secure his safe passage. Never mind that once the stolen information is put in the open, it is also in the hands of foreign enemies to the US - people that would harm both Snowden supporters and those who support the United States of America.
The only hero(es) in this will be the people that bring Snowden's escapades to an end - however that may be done. Hopefully it is done through the court system, since an evidence-based conviction is far more preferable to other solutions. Such conduct may not be popular amongst those who support Snowden, but it will save the country.
The only thing that history will write down is that some people called him a hero, but all his work will have been undone within a couple of administrations - as proven by Reagan.