In 2013 Laura Poitras received encrypted emails promising revelations of secret United States government surveillance. She flew with reporter Glenn Greenwald to Hong Kong to meet whistleblower Edward Snowden. The events that transpired became her Academy Award winning documentary Citizenfour. Poitras filmed Snowden in a Hong Kong hotel for nearly a month. When she suspected she was being followed she left Hong Kong for Berlin. In fear that the footage would be lost in the United States, Poitras edited the footage in Berlin until it was ready for release at the New York Film Festival in 2014. The Guardian and The Washington Post jointly received the Pulitzer Prize for Public Service in 2014, for their coverage of Snowdon's part in leaking secret documents, revealing the scope of the NSA's surveillance program, which was featured in CitizenFour.