Context of Citizenfour, RADiUS presents, in association with Participant Media, in association with HBO Documentary Films, in co-production with Bertha Foundation, BRITDOC Circle, Channel 4, in co-production with Norddeutscher Rundfunk NDR, Bayerischer Rundfunk BR ; a film by Laura Poitras ; directed, filmed, and produced by Laura Poitras ; produced by Mathilde Bonnefoy ; produced by Dirk Wilutzky ; a Praxis Films production