Substack wanted to be neutral. Its tolerance of Nazis proved divisive.

But facing a revolt from some of its writers and readers, the San Francisco-based start-up shifted course Monday, banning five obscure accounts that it said had violated its policies. The move, first reported by the Substack-based tech blog Platformer, did not affect larger accounts linked with right-wing extremism, the company confirmed to The Washington Post.

“We want to support and are committed to free expression and a free press, but that doesn’t mean there are not guardrails,” said Hamish McKenzie, one of the site’s three co-founders and leaders.

In an era of social media clickbait and economic woes for mainstream outlets, Substack has emerged as a potent force in media and culture by billing itself as a place where anyone can start a publication, build a loyal following and make money doing it. Its hands-off approach to its writers’ politics helped lure contrarian commentators such as Andrew Sullivan, Glenn Greenwald and Matt Taibbi away from large traditional media outlets.

But as it has blossomed into a home for a diverse array of voices from both right and left, the uproar over Nazis on the site shows cracks emerging in its “anything goes” ethos.

Monday’s announcement came amid growing pressure from hundreds of Substack’s writers, including names like author Margaret Atwood, technologist and critic Molly White, and Platformer’s Casey Newton, who have abandoned or threatened to leave the site unless its leaders reconsider its policies.

“Writers are trying to make a living,” said Casey Lewis, who runs a Substack focused on consumer insights and Gen Z trends called After School. “It’s hard enough to get someone to subscribe and pay for your words, but then have people start canceling their subscriptions, not for anything you said, but because of something the company does.”

Substack’s move to take down a handful of openly pro-Nazi accounts represents a bid to stem the exodus of left-leaning writers and readers without alienating the site’s prominent conservatives. But some writers were quick to dismiss it as too little, too late.

“It’s honestly insulting, both to writers and readers on the platform, that they think they can shut up those of us who have serious concerns with such a meager gesture,” said White, a software engineer and cryptocurrency critic who left Substack this month to self-host her newsletter.

Others worried that the damage to the site’s image has been done.

“I don’t want to meet my dad’s friends and I say I write on Substack and they go, ‘Oh, that’s the racist site, right?’” said Ryan Ozawa, who runs a Substack newsletter called Hawaii Bulletin dedicated to start-ups and innovation in Hawaii.

Substack allows writers to set up their own newsletters, send them to subscribers and charge for different tiers of subscriptions, keeping 90 percent of the revenue while the site takes 10 percent. Launched in 2017, its self-serve model has attracted commentators ranging from the liberal American historian Heather Cox Richardson to the right-leaning former New York Times columnist Bari Weiss to finance, culture and lifestyle writers.

While most Substack writers have much smaller followings, its top earners can rake in upward of $1 million per year — helping the site lure well-known pundits from much larger media organizations. While its writers span the political spectrum, some of its top earners, according to the site’s leader boards, are those who routinely criticize “woke” politics and “cancel culture.”

Even in its short six-year history, the company has sparked controversy over its laissez faire approach to content moderation. It was criticized during the coronavirus pandemic for hosting influential anti-vaccine voices, who used Substack to promote unfounded claims that ran afoul of major social media companies’ misinformation policies. The company’s founders have consistently rebuffed calls to rein in controversial views, writing in 2020: “We prefer a contest of ideas. We believe dissent and debate is important. We celebrate nonconformity.”

But after the Atlantic uncovered “scores of white-supremacist, neo-Confederate, and explicitly Nazi newsletters on Substack,” some of which the company was profiting from, scrutiny of its content policies intensified.

Befitting Substack’s status as a hub for discourse about free speech and its limits, much of the debate has played out on its various newsletters, with some of its most prominent voices weighing in. Those who have criticized the company’s stance include First Amendment lawyer Ken White, investigative journalist Marisa Kabas and Newton, who had pledged last week to leave the site if it didn’t “remove all pro-Nazi material.”

Others, including Weiss and the evolutionary biologist Richard Dawkins, have defended it, signing on to a post by fellow Substack writer Elle Griffin titled “Substack shouldn’t decide what we read.” The post endorses Substack’s preferred approach of giving individual writers the ability to moderate their own comment sections as they see fit.

In December, some 250 Substack authors wrote an open letter to the company titled “Substackers against Nazis,” calling on it to ban any accounts that traffic in “white nationalism.” Noting that Substack does appear to enforce its rules against some types of content, such as pornography, the group asked the company’s founders: “Is platforming Nazis part of your vision of success? Let us know — from there we can each decide if this is still where we want to be.”

Substack’s initial response only fueled the fire. In a Dec. 21 post, McKenzie wrote, “I just want to make it clear that we don’t like Nazis either — we wish no one held those views.” But he contended that censoring or “demonetizing” them — removing their ability to make money on Substack — would only make the problem worse.

Several Substack writers said McKenzie’s apparent stand against banning Nazis prompted them to consider leaving.

“This was so avoidable, and that’s what frustrates me about it,” said Parker Molloy, author of the Present Age, a newsletter about media, culture and politics. “They could have put out a simple, ‘We’ll look into this and any post that violates our policies will be removed.’ But instead what they put out felt deliberately provocative.”

At least one of the site’s big-name writers contended that the controversy was overblown.

“I haven’t seen any evidence of an actual volume of Nazi content on this platform that warrants a flurry of attention or major concern for writers,” said Matthew Yglesias, a commentator who writes the newsletter Slow Boring. “I also think that people calling for stricter moderation regimes tend to be a little blind to the potential downsides,” he added, such as calls at some universities to ban certain forms of pro-Palestinian activism as hate speech.

But Platformer’s Newton, who has spent a decade covering content moderation by social networks, argued that “a platform that declines to remove” Nazi sympathizers “is telling you something about itself.” It was Newton who flagged six accounts to Substack on Thursday that he saw as the most blatant violators of the company’s policies, with expressions of extremism that included overt Nazi iconography. Responding directly to him, the company removed five of those six accounts.

“None of these publications had paid subscriptions enabled, and they account for about 100 active readers in total,” McKenzie said in his response to Newton that he also provided to The Post. “If and when we become aware of other content that violates our guidelines, we will take appropriate action.”

Richard Spencer and Richard Hanania, right-wing voices who have larger followings and paid subscribers on Substack, were not among those banned, with McKenzie noting that they hadn’t been found in violation of its policies. Newton declined to comment Monday on whether he will keep Platformer on the site.

Asked whether the bans mean Substack’s thinking on content moderation has evolved since December, McKenzie said, “We don’t think censorship makes problems go away, and we’ll never think that. We also don’t reflexively take actions based on accusations, since people sometimes inaccurately assign labels to views that offend them. But we do have narrow guidelines for things we don’t permit, including explicit calls for violence.”

It remains to be seen whether the move will mollify other Substack writers who have called on the company to crack down on racism and extremist views. On Monday, several writers told The Post that they were still planning to leave the site.

Banning five small Nazi publications amounts to “little more than a PR move to try to put this controversy behind them, not a real effort to address their content moderation problem,” said Paris Marx, author of the tech criticism newsletter Disconnect.

Walker Bragman, who publishes a journalism newsletter called Important Context, said he was glad to hear about the company’s decision Monday. But he found it too little, too late to change his mind. “It’s the smallest, most basic step the platform needs to take,” he said. “There’s still a ton of disinformation.”

Others acknowledged on the condition of anonymity that they’re likely to stay, citing the likelihood that they would lose subscribers — and income — by moving elsewhere.

Jessica Reed Kraus, a Substack writer whose newsletter House Inhabit covers Hollywood gossip, conspiracy theories and political culture, said she was disappointed that the site took action at all. She said Substack’s lack of censorship during the pandemic was what drew her to the site in the first place.

“I don’t believe policing content online solves anything,” she said. “I say, let adults read and think like adults.”

Lewis said she is considering moving to Beehiiv, a Substack competitor, but she’d prefer a platform where the founders keep a low profile on political and cultural issues.

“The Beehiiv guys are so online, it makes me nervous,” she said. “You say the wrong thing and then the whole platform becomes questionable. Then you’re like, what am I supposed to go to next? MailChimp?”