On Tuesday afternoon, the New York Daily News published a column by its criminal justice writer, Shaun King (above), that denounced the harrowing treatment of a 37-year-old mentally incapacitated veteran, Elliot Williams, who died from neglect in an Oklahoma jail. Earlier that day, the Daily Beast had published a long, detailed, richly reported article on Williams’s death by Kate Briquelet, and King’s column was obviously based on Briquelet’s reporting.

But as it appeared in the Daily News, King’s column provided no citation or attribution to Briquelet’s Daily Beast article. Worse, King’s column included two paragraphs that were verbatim copies from Briquelet’s article, and presented those two paragraphs without citation or even quotation marks. At first glance, it looked like a classic case of plagiarism, with King simply lifting two paragraphs and passing them off as his own. And the Daily Beast was understandably furious that their reporter’s excellent work would be pilfered without credit.

Almost instantly, multiple Daily Beast journalists and editors, in unison, ran to Twitter to proclaim to the world that King was guilty of plagiarism, a career-destroying offense (at least for most writers). Countless journalist-friends of these Daily Beast writers also immediately jumped on the bandwagon, unquestioningly echoing and amplifying this accusation against King. Predictably, the accusation was quickly re-tweeted thousands of times. Within minutes, the internet — without even hearing from King — had both accused and convicted him of the crime of plagiarism, and was eagerly preparing to carry out the sentence: giddily awaiting the announcement that he had been fired.

As it turns out, there were two problems (at least) with this accusatory journalistic mob.

First, none of the journalists who publicly accused King of plagiarism bothered to speak with King first to ask for his side of the story, nor, by all appearances, did they contact his editors. “They didn’t contact me or one person at the Daily News,” King told The Intercept. “Jim Rich, our editor-in-chief, was livid” because he “said [Daily Beast] senior staff knows him.” Nonetheless, nobody bothered to call or email them before publicly voicing the accusation. “By the time I saw it, they had tweeted it repeatedly already,” King said. (The Daily Beast’s Executive Editor Noah Shachtman — who repeatedly tweeted the accusation against King — refused to tell The Intercept if he or anyone at his magazine contacted King or Daily News editors before broadcasting the accusation; he also, oddly, even refused to provide his colleague Justin Miller’s email address so that we could ask Miller that.)

Second, at least if the Daily News editors and King (along with the documentary evidence they produced) are to believed, yesterday’s accusation against King was totally false, even though the Daily Beast’s accusatory tweets continue to be re-tweeted right through this very minute. After seeing the eruption of accusations, King posted time-stamped emails of the draft article he sent to several of his editors that morning. King’s draft fully credited Briquelet and the Daily Beast for the passages in question; the draft even included the two paragraphs in block quotes to show he was quoting her. In other words, King included exactly the correct attribution and citations in what he wrote, and plagiarized nothing.

According to a statement from the Daily News, an editor — either accidentally or through an act of deliberate sabotage — removed from King’s draft the citations to Briquelet’s article as well as King’s block quote, making it appear as though he had plagiarized those passages. The Daily News firmly stood behind King, vehemently insisting he did nothing wrong, and announced the firing of the editor responsible for these deletions (the same editor, apparently, had previously deleted attribution from King’s past columns). The editor in question ultimately took full responsibility:

But because these journalists announced King’s guilt before bothering to learn about any of this, King was widely denounced as a plagiarist. As Slate put it today, “King was ultimately vindicated, but not before experiencing a moment of abject panic.”

What happened here? Many of the journalists who joined the mob are good reporters and know better. They and their media outlets would never dream of publishing an article accusing a journalist of plagiarism without at least first trying to contact the accused and relevant editors for comment. Had they done so here, King or his editors would have almost certainly have provided the relevant emails, and the accusers would have realized that the plagiarism accusation against King was dubious at best, if not outright false.

But because they were voicing these accusations on Twitter, rather than at their own sites, they apparently felt totally liberated from the most basic journalistic standards. They evidently had no compunction about publicly accusing someone of a reputation-destroying transgression without first contacting the accused and, worse, without making any effort to gather the elementary facts. Why should journalistic standards disappear just because reporters are voicing accusations on Twitter rather than in a stand-alone article? The accusations are just as damaging, if not more so, given how easily they can spread and how impervious they are to corrections.

But there was something darker going on here. This accusatory orgy had all the characteristics of mob behavior. As soon as popular-among-their-peers Daily Beast journalists began accusing King of plagiarism, other journalists swarmed right with them, wanting to be part of the crowd as it carried out its righteous, exhilarating search-and-destroy group mission. The fact that King is a controversial and polarizing figure who is new to journalism and is sometimes still learning to navigate the landscape, while Daily Beast writers and editors tout large groups of media friends, strengthened the motivation to join the fun of the anti-King accusatory parade, all led by the cool kids of online journalism. “I guess journalism school *IS* important,” scoffed one of his journalist-accusers, underscoring King’s outsider status.

The perils of online mob behavior have finally received some overdue attention, thanks to the work of Jon Ronson, the introspective remorse of Sam Biddle, and feature stories examining the life carnage such mobs casually wreak before moving on to the next target. But it’s particularly dangerous when journalism is carried out through this mob behavior. Journalists are vulnerable to the same temptations as all other humans: They move in packs and herds, are attracted to cliques, and prefer to join rather than stand in the way of a marauding stampede. But those impulses, natural though they are, can produce reckless journalism, consecrate falsehoods, and irreparably damage someone’s reputation without cause — as yesterday demonstrated.

None of this, obviously, is to say that all criticisms of King’s journalism are invalid or that he hasn’t made serious mistakes in the past. Nor is it to deny that there are still questions worth asking about this particular incident, such as how King never noticed that attribution in his draft-columns had been repeatedly deleted before being published (though it’s also not hard to imagine that the highly prolific, two-column-a-day King did not always read every one of his columns once published but rather assumed his columns were being published as he drafted them). And, as indicated, King’s article did appear at first glance to be a clear case of plagiarism.

But no matter what one thinks of King, the plagiarism accusation that dozens of journalists helped disseminate against him yesterday turned out to be false. That happened because journalists did not move beyond “the first glance” before publicly convicting him. Whatever his sins were in this particular case, the ones that caused the spreading of these false accusations — the ones committed by his accusers — were worse. And it’s very much worth stopping to ask what the causes of this behavior were.

Once it became apparent that the plagiarism accusation against King was false, a few Daily Beast journalists began grudgingly admitting it, but from what I can tell, none apologized to King, nor deleted their accusatory tweets (thus allowing them to be re-tweeted in perpetuity). Rather than apologize or prominently admit their error, many of the loudest accusers simply shifted gears and resorted to mocking King for his denials, including his pointing out that he is a Sanders supporter and Chelsea Clinton sits on the board of the company that controls the Daily Beast (a few commendably tweeted King’s exoneration in a prominent way). Refusing to apologize and instead mocking King for his Chelsea Clinton tweet became the new way to sit at the cool kids’ table. But however mockable that point might have been, it pales in comparison to the behavior of King’s accusers and the damage they did.

Large online platforms can be potent weapons. They become even more potent when journalist-friends and colleagues join together to use their respective platforms to try to attack and destroy a common target. Like all mob behavior, that can sometimes produce some positive outcomes. But the potential to produce reckless, destructive outcomes is much greater. That’s why the use of those platforms requires great care — exactly what was missing from the start of yesterday’s online swarming.