Edward Snowden, when we see him at the beginning of Laura Poitras' twisting corkscrew of a documentary, is remarkably calm despite the fact that his life as he knows it is over. That calm doesn't last. Poitras filmed the National Security Agency contractor over the eight days he spent in Hong Kong last year explaining to journalists Glenn Greenwald and Ewen MacAskill the depth — and unconstitutionality — of the NSA's data-collection program. ''I don't want to live in a society that does these sort of things,'' he says. Poitras presents him at arm's length, not meddling into his privacy (duh), yet we relate to his fear and vulnerability. As he stares out a 10th-floor window, we share the view of the city below. How awful would it feel to walk out there and be under constant supervision? When a fire alarm goes off in the hotel, we flinch. In an inadvertent cinematic touch, his shirt color changes — from white to gray to black — as he transforms from an ordinary guy into a fugitive, seeking refuge from U.S. espionage charges. (Russia eventually offered asylum.)
For all its brio, the film is overcautious about pointing fingers. Snowden cites his disappointment in Barack Obama as a motivation for his whistle-blowing (a fact sure to tie both lovers and haters of Obama in ideological knots), but the president appears only once. In person, on news footage, that is. The finale, set in a Moscow hotel room, tells of new informants and the Niagara of revelations still to come. Greenwald and Snowden converse via pen and paper, for fear that the room could be bugged. And after Greenwald rips up the pages, the camera lingers disturbingly on one little scrap. It reads: ''POTUS.'' B+
