The former American intelligence operative Edward Snowden is still trapped in transit. A previous NSA whistleblower tells Channel 4 News about the "ruthless" government campaign against him.

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Holed up in Moscow airport, his home of three weeks from Tuesday, Edward Snowden is still considering his options. After meeting with human rights activists on Friday there was strong speculation that the NSA whistleblower would seek temporary asylum in Russia, writes Rebecca Tyers.

While US officials expressed outrage that Russia would grant Snowden a "propaganda platform", the rest of the world wondered why an American citizen, even in exile, would be denied the freedom of speech.

"None of this has surprised me. Why? Because I saw what he saw. The difference is it’s 12 years later," says fellow NSA whistleblower Thomas Drake.

Thomas Drake is a former NSA senior executive who began working for the government intelligence organisation on 11 September 2001. After noticing wrongdoing within the NSA, he went through all the correct legal proceedings to report what he had seen, including contacting the NSA inspector general, Department of Defence inspector general and the House and Senate congressional intelligence committees.

I've had to spend five years of my life under the gun. Thomas Drake, former NSA executive

When this failed, in February 2006 Drake made contact with a journalist from the Baltimore Sun. As a fellow whistleblower, he knows exactly what Edward Snowden is going through.

"It’s similar in that once again the Department of Justice is using the espionage act in an extraordinarily heavy-handed way, essentially treating Edward Snowden as a spy. That’s exactly the way they treated me. The only difference is that in order to retain his freedom, he escaped the United States".

Thomas Drake did not leave. He was instead charged with a 10-felony-count indictment, five counts under the espionage act, and faced upwards of 35 years in prison.

Under a weight of evidence in Drake’s favour, the government dropped all charges in July 2011 before the case even went to court and he ended serving only a year’s probation for "exceeding authorised use of a computer". The damage, however, had been done.

"I’ve had to spend five years of my life under the gun," he said. "It was a devastatingly high price I paid. Severe debt, taking out a second mortgage on my home, going through most of my retirement, extraordinary personal costs I don’t share in public.

Creating a new life

"I’ve had to create a whole new life. Fortunately I’ve had a strong support network but it’s nothing like where I was. All of that is gone."

Someone who knows the difficulties of protecting whistleblowers is Kathleen McClellan from the National Security Human Rights Council of the Government Accountability Programme. It aims to empower occupational free speech and has worked extensively with Thomas Drake and other whistleblowers.

"There is a long tradition in the United States of protecting liberty at all cost," says Kathleen "That said, whistleblowers should not have to sacrifice their conscience for their career. Government servants should be able to feel like they are serving the American public. That’s why a lot of people go to work for the government.

"So the fact that you should have to choose your freedom over your conscience is very antithetical to government service in this country. I think most whistleblowers don’t feel like they had a choice. They saw something and then they had to speak up because their oath was to protect the constitution."

Another NSA whistleblower, Bill Binney, agrees. "The public is becoming more and more concerned about the issue of surveillance... It’s not constitutionally acceptable. I’m hoping that this concern will be taken in some form of action."

Liberty, at any cost?

Bill Binney was held at gunpoint by the FBI and forced into retirement by the NSA yet has never been charged with any misdemeanors by the government despite three separate investigations.

It should be a comfort to Edward Snowden that neither Bill nor Thomas regret their decision to blow the whistle and both have spoken out to defend him.

But while Snowden spends another day in his unofficial aviation prison Thomas Drake acknowledges the similarities in their situations and how it could all have been different.

"I am the only one in this unprecedented, extraordinary ruthless campaign against truth tellers and whistleblowers by the Obama administration... who was able to keep my freedom, keep my liberty, keep my rights."

Rebecca Tyers works at the Washington bureau of Channel 4 News