This past January, Laura Poitras received a curious e-mail from an anonymous stranger requesting her public encryption key. For almost two years, Poitras had been working on a documentary about surveillance, and she occasionally received queries from strangers. She replied to this one and sent her public key — allowing him or her to send an encrypted e-mail that only Poitras could open, with her private key — but she didn’t think much would come of it.

http://www.nytimes.com/2013/08/18/magazine/laura-poitras-snowden.html?_r=0