In June 2013, Laura Poitras and reporter Glenn Greenwald flew to Hong Kong for the first of many meetings with Edward Snowden. She brought her camera with her.
The documentary is good and the story telling is easy to follow but I felt that it was too artificially turned into a spying movie ... even when it is the closest to a real spying movie, but it doesn't have to recall fiction.
In any case, I think the positive reviews and the importance of the documentary is much more because of what Snowden had to say and tell us about US' NSA, not that much about the documentary itself.