Republicans have been complaining of House Democrats interviewing witnesses in their impeachment inquiry in closed-door sessions then leaking selective testimony to the media.

Now, the Media Research Center has found that nearly six of 10 impeachment reports by ABC, CBS and NBC over the past month have been based on anonymous sources.

"Mostly to pass along damning accusations against the president that cannot be independently verified," said the report on MRC's Newsbusters site.

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"From September 24 – the day the impeachment inquiry was announced – to October 24, these three broadcast networks devoted 322 minutes to the probe in their evening newscasts, across 140 separate news segments. Of those, more than half (82, or 57%) relied at least in part on information from anonymous sources," MRC found.

On ABC's "World News Tonight," 54% of the stories were based on anonymous sources. For CBS "Evening News" it was 60% and for NBC's "Nightly News" 60%.

A policy piece by the Society of Professional Journalists cautions strongly against the use of anonymous sources, noting: "Some organizations do not allow anonymous sources except in the most vital news stories."

And the New York Times stylebook explains quoting the faceless and nameless should be a last resort.

"Anonymity must not become a cloak for personal attacks," the Times says. "The vivid language of direct quotation confers an unfair advantage on an unnamed speaker, and turns of phrase are valueless to a reader who cannot assess the source."

Explained Newsbusters: "Put another way, every source who talks to a reporter is promoting the facts and spin that best reflects their agenda. When President Trump or House Speaker Nancy Pelosi speaks on camera, viewers can make up their own minds about how much to trust what is said. But when a source hides behind the cloak of anonymity, that source's agenda is also hidden from the audience."

Apparently that didn't stop the networks from seeing that their viewers were "bombarded on a near-nightly basis" with those reports.

Some are even worse than "anonymous," Newsbusters pointed out.

ABC chief White House correspondent Jonathan Karl recently had a story quoting an anonymous source whose report was "relayed secondhand by a separate anonymous source."

From that, Americans were told President Trump's phone call with the president of Ukraine was "crazy," the report explained.

And on CBS, chief Washington correspondent Major Garrett "reported on one anonymous source's description of a memo written by a second anonymous individual, in which it was alleged that a third anonymous individual, who claimed to have listened to the phone call, contended that the call had been unrelated to national security."

"Truly bulletproof stuff," Newsbusters commented.

Earlier this month, the Society of Professional Journalists' Florida chapter said it wanted to trademark the words "fake news." If successful, it would be able to restrict who uses that term and how it is applied.

The Hill reported the Florida journalists note 40% of Republicans think the term "applies to accurate reporting that casts politicians they support in a negative light."

But the application is unlikely to be approved, The Hill said, citing reporter Emily Bloch, who explained the intent is to compel people to "think about what fake news is, and what it means to them."

"This is satire. It's a joke. But it's a joke with a point, and as any student of public discourse will tell you, a joke sometimes hits harder than the truth," wrote Bloch in an op-ed in Teen Vogue.

She makes clear her disdain for Trump and his application of the term to establishment media.

"And if anyone accuses us of trolling the president, well, nothing else seems to work with him, so what do we have to lose?" she said.

Bloch wrote that the SPJ branch already "is sending Donald Trump cease and desist letters over the use of the term 'fake news.'"

She complains Trump is "constantly devaluing our work."

"President Donald Trump using the term 'fake news' so freely is something my colleagues and I find really troubling. And it's not just the nature of Trump’s use of the term; it's the volume too. According to Factba.se, a site launched to track the president’s public comments, Trump has referenced the term over 1,200 times since he took office, making for an average of more than once a day," she wrote.