The press, the public and democracy itself have always relied on people of conscience speaking out as witnesses of corruption, misconduct and the abuse of power. The whistleblower’s vital role is even protected by federal law. But the Obama administration has been waging what filmmaker Robert Greenwald calls a “war on whistleblowers,” particularly those accused of exposing information related to national security. His new film “War on Whistleblowers: Free Press and the National Security State,” tells the story of four government employees who, in the post 9/11 era, spoke out against official wrongdoing and paid a heavy price. We caught up with Greenwald to learn more.

First, watch the trailer:

Lauren Feeney: Introduce us to the whistleblowers featured in your film.

Robert Greenwald: The first is Franz Gayl, an amazing American hero who spoke up, took on the military industrial complex and was responsible for saving many, many lives by forcing the institutions to introduce the MRAP (Mine-Resistant Ambush Protected vehicle) in Iraq instead of what they had previously been using. By the soldiers’ admission and by quite a few others, this was literally a lifesaver of enormous importance.

The second whistleblower is Michael DeKort, who discovered that radios being put on Coast Guard boats were not waterproof, which is really hard to even believe.

The third whistleblower is Thomas Drake, who spoke out loudly about the fact that our phones were being tapped, and that there was surveillance software available that could have done a better job, a legal job, and a more inexpensive job that was not used because of a competing project. He was accused and cited under the Espionage Act.

And the fourth case is Tom Tamm, whose revelations were part of what led to the original New York Times story about the Bush administration’s warrantless wiretapping. He had worked for the FBI, and his father had worked there, and he lost his job and paid a tremendous price for speaking up.

Feeney: You call this a “war on whistleblowers.” Why the crackdown?

Greenwald: The national security state — the ideologies and institutions created by the 1947 National Security Act, like the CIA and the National Security Council — believes in all secrets, all the time, and is leading the charge for silence. It is important that the administration and citizens resist this pressure. The crackdown on the national security whistleblowers by the Obama administration is a cause of great concern and unhappiness for whistleblowers, reporters and transparency experts.

Feeney: What effect does this “war on whistleblowers” on our democracy?

Greenwald: The effect of silence and secrets is devastating. Think of all the important stories and issues that have been exposed only because of whistleblowers. We must fight hard to make sure that tradition is upheld. Our action guide tells you what you can do to protect whistleblowers and investigative reporters.

Robert Greenwald is an activist and filmmaker whose documentaries include Uncovered: The War on Iraq, Outfoxed: Rupert Murdoch’s War on Journalism and Koch Brothers Exposed.