What Edward Snowden has done is an amazingly brave and courageous act of civil disobedience.

Like me, he became discomforted by what he was exposed to and what he saw: the industrial-scale systematic surveillance that is scooping up vast amounts of information not only around the world but in the United States, in direct violation of the fourth amendment of the U.S. constitution.

The NSA programs that Snowden has revealed are nothing new: they date back to the days and weeks after 9/11. I had direct exposure to similar programs, such as Stellar Wind, in 2001. In the first week of October, I had an extraordinary conversation with NSA's lead attorney. When I pressed hard about the unconstitutionality of Stellar Wind, he said:

"The White House has approved the program; it's all legal. NSA is the executive agent."

It was made clear to me that the original intent of government was to gain access to all the information it could without regard for constitutional safeguards. "You don't understand," I was told. "We just need the data."

In the first week of October 2001, President Bush had signed an extraordinary order authorizing blanket dragnet electronic surveillance: Stellar Wind was a highly secret program that, without warrant or any approval from the FISA court, gave the NSA access to all phone records from the major telephone companies, including U.S.-to-U.S. calls. It correlates precisely with the Verizon order revealed by Snowden; and based on what we know, you have to assume that there are standing orders for the other major telephone companies.

It is technically true that the order applies only to meta-data. The problem is that in the digital space, metadata becomes the index for content. And content is gold for determining intent.

This executive fiat of 2001 violated not just the fourth amendment, but also FISA rules at the time, which made it a felony – carrying a penalty of $10,000 and five years in prison for each and every instance. The supposed oversight, combined with enabling legislation – the FISA court, the congressional committees – is all a kabuki dance, predicated on the national security claim that we need to find a threat. The reality is, they just want it all, period.

So I was there at the very nascent stages, when the government – willfully and in deepest secrecy – subverted the constitution. All you need to know about so-called oversight is that the NSA was already in violation of the Patriot Act by the time it was signed into law.

When I was in the U.S. air force, flying an RC-135 in the latter years of the cold war, I was a German-Russian crypto-linguist. We called ourselves the "vacuum-cleaner of the sky" because our capability to gather information was enormous at the time. But it was always outward-facing; we could not collect on U.S. targets because that was against the law. To the U.S. government today, however, we are all foreigners.

I became an expert on East Germany, which was then the ultimate surveillance state. Their secret police were monstrously efficient: they had a huge paper-based system that held information on virtually everyone in the country – a population of about 16-17 million. The Stasi's motto was "to know everything."

So none of this is new to me. The difference between what the Bush administration was doing in 2001, right after 9/11, and what the Obama administration is doing today is that the system is now under the cover and color of law. Yet, what Snowden has revealed is still the tip of the iceberg.

General Michael Hayden, who was head of the NSA when I worked there, and then director of the CIA, said, "We need to own the net." And that is what they're implementing here. They have this extraordinary system: in effect, a 24/7 panopticon on a vast scale that it is gazing at you with an all-seeing eye.

I lived with that dirty knowledge for years. Before 9/11, the prime directive at the NSA was that you don't spy on Americans without a warrant; to do so was against the law – and, in particular, was a criminal violation of FISA. My concern was that we were more than an accessory; this was a crime and we were subverting the constitution.

I differed as a whistleblower to Snowden only in this respect: in accordance with the Intelligence Community Whistleblower Protection Act, I took my concerns up within the chain of command, to the very highest levels at the NSA, and then to Congress and the Department of Defense. I understand why Snowden has taken his course of action, because he's been following this for years: he's seen what's happened to other whistleblowers like me.

By following protocol, you get flagged – just for raising issues. You're identified as someone they don't like, someone not to be trusted. I was exposed early on because I was a material witness for two 9/11 congressional investigations. In closed testimony, I told them everything I knew – about Stellar Wind, billions of dollars in fraud, waste and abuse, and the critical intelligence, which the NSA had but did not disclose to other agencies, preventing vital action against known threats. If that intelligence had been shared, it may very well have prevented 9/11.

But as I found out later, none of the material evidence I disclosed went into the official record. It became a state secret even to give information of this kind to the 9/11 investigation.

I reached a point in early 2006 when I decided I would contact a reporter. I had the same level of security clearance as Snowden. If you look at the indictment from 2010, you can see that I was accused of causing "exceptionally grave damage to U.S. national security." Despite allegations that I had tippy-top-secret documents, In fact, I had no classified information in my possession, and I disclosed none to the Baltimore Sun journalist during 2006 and 2007. But I got hammered: in November 2007, I was raided by a dozen armed FBI agents, when I was served with a search warrant. The nightmare had only just begun, including extensive physical and electronic surveillance.

In April 2008, in a secret meeting with the FBI, the chief prosecutor from the Department of Justice assigned to lead the prosecution said, "How would you like to spend the rest of your life in jail, Mr Drake?" – unless I co-operated with their multi-year, multimillion-dollar criminal leak investigation, launched in 2005 after the explosive New York Times article revealing for the first time the warrantless wiretapping operation. Two years later, they finally charged me with a ten felony count indictment, including five counts under the Espionage Act. I faced upwards of 35 years in prison.

In July 2011, after the government's case had collapsed under the weight of truth, I plead to a minor misdemeanor for "exceeding authorized use of a computer" under the Computer Fraud and Abuse Act – in exchange for the DOJ dropping all ten felony counts. I received as a sentence one year's probation and 240 hours of community service: I interviewed almost 50 veterans for the Library of Congress veterans history project. This was a rare, almost unprecedented, case of a government prosecution of a whistleblower ending in total defeat and failure.

So, the stakes for whistleblowers are incredibly high. The government has got its knives out: there's a massive manhunt for Snowden. They will use all their resources to hunt him down and every detail of his life will be turned inside out. They'll do everything they can to "bring him to justice" – already there are calls for the "traitor" to be "put away for life."

He can expect the worst; he knows that. He went preemptively overseas because that at least delays the prying hand of the U.S. government. But he could be extracted by rendition, as he has said. Certainly, my life was shredded. Once they have determined that you are a "person of interest" and an "enemy of the state", they want to destroy you, period.

I am now reliving the last 12 years from what's been disclosed in the past week. I feel a kinship with Snowden: he is essentially the equivalent of me. He saw the surveillance state from within and saw how far it's gone. The government has a pathological incentive to collect more and more and more; they just can't help themselves – they have an insatiable hoarding complex.

Since the government unchained itself from the constitution after 9/11, it has been eating our democracy alive from the inside out. There's no room in a democracy for this kind of secrecy: it's anathema to our form of a constitutional republic, which was born out of the struggle to free ourselves from the abuse of such powers, which led to the American revolution.

That is what's at stake here: to an NSA with these unwarranted powers, we're all potentially guilty; we're all potential suspects until we prove otherwise. That is what happens when the government has all the data.

The NSA is wiring the world; they want to own internet. I didn't want to be part of the dark blanket that covers the world, and Edward Snowden didn't either.

We are seeing an unprecedented campaign against whistleblowers and truth-tellers: it's now criminal to expose the crimes of the state. Under this relentless assault by the Obama administration, I am the only person who has held them off and preserved his freedom. All the other whistleblowers I know have served time in jail, are facing jail or are already incarcerated or in prison.

That has been my burden. I've dedicated the rest of my life to defending life, liberty and pursuit of happiness. I didn't want surveillance to take away my soul, and I don't want anyone else to have to live it.

For that, I paid a very high price. And Edward Snowden will, too. But I have my freedom, and what is the price for freedom? What future do we want to keep?