'Snowden' Joseph Gordon-Levitt plays the NSA whistleblower in the biopic, which also stars Shailene Woodley, Melissa Leo and Nicolas Cage and will screen in an out-of-competition slot. Oliver Stone's biopic Snowden, starring Joseph Gordon-Levitt as the NSA whistleblower, will get its European premiere at the 64th edition of the San Sebastian Festival. The film will screen in the Spanish festival's official selection in an out-of-competition slot. Open Road will release it in the United States on Sept.