To make sure the screenplay was not hacked or leaked, Oliver Stone wrote the script on a single computer with no Internet connection.
Oliver Stone visited the real Edward Snowden after filming wrapped and showed him a work-in-progress cut of the film.
Edward Snowden's parents attended a screening of the film, and praised Joseph Gordon-Levitt for his portrayal of their son. The actor said it was the most meaningful encouragement he has ever received for a performance.
The real Edward Snowden advised Oliver Stone that the NSA's command centers are actually run on tight budgets and are far less glamorous than they appear in movies and TV shows.
Joseph Gordon-Levitt pledged to donate his entire salary from the film to "help facilitate the conversation" about the relationship between technology and democracy.