Last May, Edward Snowden flew to Hong Kong, ensconced himself in a room in an upscale hotel and released his huge cache of documents exposing the U.S. Government’s domestic spying programs. Guardian columnist Glenn Greenwald and documentary filmmaker Laura Poitras were with him in Hong Kong for much of that week. Now, Poitras has made a full-length documentary about Snowden called “CitizenFour.” She spoke to “Press Play” producer Matt Holzman about it.