Anonymous sources both unsurprising and necessary

President Trump used a gathering of conservative activists to launch yet another missile attack against the news media. Unethical reporters “make up stories and make up sources,” he fumed. “They shouldn’t be allowed to use sources unless they use somebody’s name. Let their name be put out there.”

Those statements are revealing and alarming. By using the word “allowed,” the president implies that some force or mechanism should have the power to control the press.

Here’s what else he said: The news media “will never represent the people and we’re going to do something about it.” What does “do something” mean? It’s not an idle threat. As a candidate, Trump talked often about loosening libel laws. And his press office recently barred news organizations he doesn’t like from attending a White House briefing.

Perhaps someone should slip a copy of the First Amendment into the president’s daily intelligence report, in the somewhat vain hope that he actually reads those things.

The news media is hardly perfect. A Time reporter covering the early days of the Trump administration tweeted that a bust of Martin Luther King Jr. had been removed from the Oval Office. He was wrong, a stupid and sloppy mistake on an incendiary topic that should never have happened.

News outlets can get careless in the use of anonymous sources, and ignore the admonition in The New York Times ethics code that such sources should be used only as “a last resort.” And every president complains about leaks, including Barack Obama, who prosecuted more whistleblowers than any previous president.

But Trump’s assault on the media is particularly cynical and disingenuous. As the Associated Press reported, “members of the White House team regularly demand anonymity when talking to reporters.” Added New York Times editor Dean Baquet on CNN: “He’s been an anonymous source throughout his career, especially when it helped him and when it burnished his reputation.”

Trump’s “running war” with the press, as he calls it, is only a skirmish in a much larger battle. He is trying to undermine the whole concept of verifiable facts, produced by independent sources of information, that contradict his own view of the world.

Take an intelligence report, produced by the Department of Homeland Security and leaked to the press, which rebuts Trump’s claim that draconian control of refugees is needed to protect national security. The administration went nuts, with one “senior official” complaining to The Wall Street Journal, “This is not the intelligence assessment the president asked for.”

Again, revealing language. The clear meaning: The president “asked for” a report that would validate his flawed reasoning, not one produced by independent researchers. In truth, said the Journal, the report’s findings “track similar studies by think tanks and news organizations.” It also agrees with the conclusions of three federal courts that blocked Trump’s executive order on refugees.

But in Trump World, the experts are wrong. The White House gets to define its own facts.

News organizations have to be very careful in using anonymous sources. They should follow the Times practice of making sure a top editor knows the identity of every one quoted. And they should describe for their stakeholders, as closely as possible, who the sources are, why they are reliable and why they need to remain secret.

However, as Trump pursues his war against facts and fact-finders, professionals are going to fight back. Many of them -- scientists, intelligence officers, economists, lawyers, researchers of all kinds -- have spent their careers devoted to the principle that Trump denies. Namely, that the world can be described, analyzed, measured and evaluated, independent of political prejudices and pressures.

And it’s totally understandable that certain sources want to remain anonymous.

“In an administration that has expressed so much distaste for