slate.com/articles/news_and_politics/war_stories/2014/10/citizenfour_review
Snowden's claim as a whistleblower, exposing the National Security Agency's violations of civil liberties, rests on some of the documents that he leaked...However, many other documents—which he downloaded at the NSA facility in Hawaii and turned over to Poitras and the Guardian's Glenn Greenwald in Hong Kong...also detail NSA intercepts of email and cellphone conversations by Taliban fighters in Pakistan; assessments of CIA assets in several foreign countries; and surveillance of cellphone calls "worldwide" that (in the Post's words) allows the NSA "to look for unknown associates of known intelligence targets by tracking people whose movements intersect."
...Whatever you think about foreign intelligence operations, the NSA's core mission is to intercept communications of foreign governments and agents. If Snowden and company wanted to take down an intelligence agency, they should say so. But that has nothing to do with whistleblowing or constitutional rights.
At one very interesting point in the film, Snowden tells Poitras and Greenwald, "Some of these documents are legitimately classified," and their release "could do great harm" to intelligence sources and methods. He adds, "I trust you'll be responsible" in handling them... 
