Porn star Stormy Daniels speaks outside New York federal court in April. (Mary Altaffer/AP)

Greta Van Susteren is anchor of Voice of America’s “Plugged In With Greta Van Susteren.”

Freedom of the press is so vital to American society that this occupation is the only one expressly safeguarded by name in the First Amendment: “Congress shall make no law . . . abridging the freedom of speech, or of the press.” Without a free press, all our other freedoms are endangered. It is our best defense against tyranny.

With that protection comes a deep responsibility to scrutinize those in power and to report fully and fairly. But to fulfill that responsibility, news organizations must also insist on maintaining the highest standards of credibility.

In recent months, the media has come under withering criticism. Some of this has been unwarranted, but some has been very much deserved. Specifically, the allegations of deeply disturbing predatory behavior inside leading news organizations, including CBS, Fox News, NBC, NPR and the New York Times, have shaken public faith in the media. But what I and many others who work in the media know is that these organizations are not alone — nor has the full range of media wrongdoing been detailed. One major reason that journalists and the public have not learned all the facts: non-disclosure agreements.

Many broadcast news organizations use NDAs and confidentiality clauses to muzzle current and past employees. If an employee dares to speak out to expose media wrongdoing, a news organization and its parent corporation will unleash a legion of lawyers. Particularly in television news, no individual has the financial resources to combat a Comcast or a 21st Century Fox.

Why would employees sign an NDA? I’m a lawyer, and over the course of more than 20 years at major news organizations, I signed multiple NDAs. They were routine, and when I signed them, they seemed reasonable. I fully expected the corporations I worked for and their executives to follow the law, to fulfill their responsibilities and, yes, to act decently. Why would a news organization muzzle an employee to hide bad behavior? Weren’t we all on the same page, working to shine a light on abuses of power?

I realize now that my basic assumptions were wrong. It is absurd to require NDAs for employees of broadcast news organizations — whose right to speak freely is already protected by the First Amendment. Moreover, what is so secret in a news organization that it needs draconian protection? Newsgathering isn’t like sharing Coca- Cola’s secret formula with Pepsi. There are no real trade secrets in TV news. Everything I did on my shows on three different networks — from segment times, to interviews, to video clips — was immediately in the public domain. The only thing that needs hiding is bad behavior, which, sadly, is hardly limited to sexual harassment.

Further undermining their credibility, the same news organizations that insist on muzzling their employees pursue some of their biggest scoops by encouraging outside sources to violate their own NDAs. CBS was happy to have Stormy Daniels violate the confidentiality clause in her settlement agreement and go on the record against President Trump. So my question is: Has the network released all its employees from their confidentiality clauses or NDAs? I would love for CBS to tell us.

But this is much bigger than a splashy stripper suing the president. If news organizations didn’t press sources to reveal secret information, we wouldn’t have the Pentagon Papers or Watergate or uncover government duplicity such as Iran-contra or the truth behind the Flint, Mich., water crisis.

Yet when news organizations and their executives are the perpetrators, whether it is sexual harassment, discrimination, unfair hiring or firing, or other actions inconsistent with their obligations under the Constitution, they seek to hide it. When news organizations themselves stray, suddenly transparency and free speech are not so appealing.

Too many media organizations seek to resolve their bad behavior in secret, via arbitration, rather than in court, where proceedings are public. The settlements, usually including confidentiality clauses, are designed to be sealed. And when there are multimillion-dollar payouts, among those kept in the dark are media-company shareholders.

As for the industry argument that without NDAs, employees would wrongfully disparage and tell lies about the media companies’ works, the networks and other organizations have plenty of legal remedies.

If news organizations want to honor their constitutional responsibilities, do their best job and restore some lost credibility with the American people, they need to do the right thing: release all current and past employees from their NDAs (except when they involve the rare legitimate business secret) and move disputes into the open. Justice Louis Brandeis’s quote — “sunlight is said to be the best of disinfectants” — has become a maxim because it is true.

If news organizations don’t move to ban NDAs, it’s time we all ask: What are they hiding?