Watching Snowden’s pivotal moments in ‘Citizenfour’

Filmmaker Laura Poitras captured the moment former NSA contractor Edward Snowden revealed himself as the source behind a massive document leak of classified surveillance in 2013. Two years later, Snowden’s story is the subject of the Oscar-nominated documentary, “Citizenfour.” Jeffrey Brown speaks with Poitras and journalist Glenn Greenwald about how those pivotal moments came to life on screen.