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"How many sets of the documents you disclosed did you make, and how many different people have them? If anything happens to you, do they still exist?" a questioner asked Greenwald in a livechat on the website of The Guardian, to whom Snowden has provided some of the documents.
Here is his answer:
"All I can say right now is the US Government is not going to be able to cover this up by jailing or murdering me. Truth is coming, and it cannot be stopped."
Many members of Congress have suggested that Snowden is a "traitor" or committed an "act of treason."
In the chat, Snowden also said that he fled to Hong Kong over Iceland — his preferred destination for asylum — because of travel restrictions for NSA employees.
"Leaving the US was an incredible risk, as NSA employees must declare their foreign travel 30 days in advance and are monitored," Snowden wrote.
"There was a distinct possibility I would be interdicted en route, so I had to travel with no advance booking to a country with the cultural and legal framework to allow me to work without being immediately detained. Hong Kong provided that. Iceland could be pushed harder, quicker, before the public could have a chance to make their feelings known, and I would not put that past the current US administration."