Where does transparency meet irresponsibility? Right at the line that BuzzFeed’s editor Ben Smith approached Tuesday and decided to step over in the name of serving citizens’ best interests.

With caveats and explanations aplenty, Smith published a 35-page “dossier” — actually just a bunch of scurrilous allegations dressed up as an intelligence report meant to damage Donald Trump.

Smith said he did so because his, and BuzzFeed’s, preference and philosophy is, essentially, “When in doubt, publish.” But at many other news organizations, the rule is caution: “When in doubt, leave it out.”

In this case, the doubt should have prevailed. News organizations and government officials have known for months that this information, if it can be called that, existed. But despite many attempts, the claims about Trump’s behavior and relationships in Russia could not be verified.

Thus, major newspapers and magazines sat on them. In October, the Washington bureau chief of Mother Jones, David Corn, wrote a story based on the file but stopped well short of publishing the specifics.

(Bastien Inzaurralde/The Washington Post)

Why? Because he couldn’t verify them.

So what changed and blew this out into the public eye? Not just BuzzFeed’s data dump, but a series of events. Intelligence agencies summarized the “dossier” and included it in material given to Trump and President Obama.

CNN published a story Tuesday saying that much. And with the door cracked open, BuzzFeed pushed through. In doing so, the digital behemoth — which for years has balanced a tension between its start as a lighthearted click factory and, under Smith and a serious news team, a purveyor of investigative journalism and breaking news — set off a fierce debate.

“Publishing this dossier reflects how we see the job of reporters in 2017,” Smith wrote. In other words, readers are grown-ups and deserve to be treated as such, not paternalistically protected from information that might upset them. True enough, but it avoids the larger point: It’s a bad idea, and always has been, to publish unverified smears.

The decision certainly resulted in clicks. It also brought approval and disapproval, in some cases from unexpected quarters.

Richard Tofel, president of ProPublica, praised the decision: “Kudos to @buzzfeedben and his team for publishing the dossier. Once CNN story out, citizens should have evidence to consider for themselves.”

Journalist Michael Tracey noted that while WikiLeaks had been “relentlessly attacked” for publishing verified, authentic information, BuzzFeed was being “cheered for publishing what appears to be a total sham.”

(The Washington Post)

And in the New York Post, columnist and longtime magazine editor John Podhoretz made a solid point: “In my experience, there is no source of whom you need to be more skeptical, and whose information you need to verify to the letter before you can even begin to think of publishing it, than an ‘intelligence’ source.”

Once BuzzFeed published, of course, the dam burst. Slate followed, publishing the documents itself, and anyone in the world had access with a few keystrokes.

Trump — who gave his first news conference Wednesday — immediately took to Twitter to brand the information “fake news” and to blame a political witch hunt. The publication of the documents does, indeed, give fuel to the notion that the press is out to get him.

Most mainstream outlets, including The Washington Post, even now are staying away from the specifics of the report, said to be prepared by a former British intelligence official. Those media organizations don’t get much credit these days for skepticism and editorial judgment, but for the most part, they have shown it here.

I don’t fault BuzzFeed for lack of skepticism here. Smith was clear with readers that the information he was publishing couldn’t be verified and, indeed, there was no reason to believe that much of it was true. What I fault him for was plunging down a slippery ethical slope from which there is no return.

In an era when trust in the media is already in the gutter, this does absolutely nothing to help. But even that isn’t the core point, which is far simpler:

It’s never been acceptable to publish rumor and innuendo. And none of the circumstances surrounding this episode — not CNN’s story, not Trump’s dubious history with Russia, not the fact that the intelligence community made a report on it — should change that ethical rule.

For more by Margaret Sullivan, visit wapo.st/sullivan.