About Substack's Tolerance for Extremism
Jonathan M. Katz and Marisa Kabas sound the alarm
The toleration of extremism by Substack is noted in the August 7, 2025 article by Katz, co-authored and edited by Kabas, appearing on both author's websites:
Substack's extremist ecosystem is flourishing
Yup, they're still at it. by Jonathan M. Katz
Substack’s extremist ecosystem is flourishing
The app's recent swastika push alert was just the tip of the iceberg. by Marisa Kabas
In this co-authored article, Katz and Kabas point to some examples of the rising influence of Nazi content on Substack, such as a nazi symbol pushed to phones as an alert and the use by mainstream media of neo-nazi sources. They also explain in detail other examples of Nazi apologists, and follow the money behind a July 2025 infusion of one hundred million from certain investors.
Nazi Symbol Phone Alerts
Taylor Lorenz, a tech expert, reported on July 29, 2025 about having a swastika pop up as a notification, and wondered if far-right rhetoric was being pushed by major donors to Substack. Her article "Substack sent a push alert promoting a Nazi blog" is available for public view. Substack officials later admitted that allowing alerts for a neo-Nazi blog being pushed to phones was a "serious error, " but Lorenz notes that such a mistake was possible because Substack allows such content and also, as she claims, actively promotes authoritarian extremism.
Mainstreaming Nazi Sources
Content originating from a neo-Nazi on Substack was used by the New York Times to attack Zohran Mamdani of using dishonest racial information to get in to Columbia University in 2009. On July 3, 2025, the New York Times ran a piece titled "Mamdani Identified as Asian and African American on College Application." A box check by a teen college applicant is made to sound like a major scandal, including quotes from Eric Adams on how Mamdani should be investigated for exploiting his racial identity for personal gain. Born in Africa to a family from India, Mr. Mamdani, an American citizen, did not attend Columbia.
Authorship, sources, and questionable assumptions in this July 3 New York Times article are used to support this supposed scandal. Katz and Kabas explain the complicated process of how this misinformation spread.
In other words, an anti-trans Substacker used a eugenicist Substacker to launder information from a neo-Nazi and smuggled it into the most powerful paper in the country–with the help of some of that paper’s editors–in an attempt to smear a mayoral candidate of color whose leftist politics they all oppose. – Katz and Kabas
The 2023 Substack Nazi Problem
In 2023, when I'd been on Substack for a while, I heard about a number of prominent writers who left over a Nazi problem that Substack seemed to be having at the time. As a follower of Marisa Kabas at The Handbasket, I was dismayed, but simply followed her over to her own independent website. The idea of leaving Substack myself did not occur to me, since it was just a hobby for me to comment on this and that, to post this and that, and of course I wanted to keep reading and supporting the several writers I paid. Some of this background is covered in the Aug 7, 2025 article, where Katz and Kabas explain:
The last time extremism on Substack received widespread attention was in 2023, following the publication of my article in the Atlantic, “Substack Has a Nazi Problem.” (by Jonathan M. Katz)
In his Nov 2023 Atlantic article, Katz describes his investigation of some of the numerous white-supremicist, neo-Confederate, and pro Nazi newsletters he found on Substack. Substack officials responded in the New York Times on December 22, 2023 with the article "Substack Says It Will Not Ban Nazis or Extremists, which as a member of the public I would have to go to the library to actually read.
In Substack's extremist ecosystem is flourishing, Katz and Kabas review the position stated by Hamish McKenzie (Substack co-founder) – that although they do not like Nazi content, they do not believe in censorship.
Under pressure, Substack not only defended their hosting policies but also asserted that Nazis should be allowed to keep making money on their platform. “I just want to make it clear that we don’t like Nazis either—we wish no one held those views. But some people do hold those and other extreme views. Given that, we don't think that censorship (including through demonetizing publications) makes the problem go away—in fact, it makes it worse,” McKenzie wrote in a statement to the platform’s users. Nowhere did he explain how allowing Nazis and Nazi-sympathizers to make money and build large audiences on his platform would “strip bad ideas of their power.”
The backlash was swift. More than 240 Substackers, including The Handbasket’s Marisa Kabas and myself, had co-published an open letter condemning the platform’s promotion and monetization of white-nationalist newsletters. – Katz and Kabas
Substack then under the pressure of writers leaving, did ban a few (five) of their pro-Nazi sites, but now nearly two years later, it appears that such content is alive and well, and flourishing.
Marc Andreessen, Curtis Yarvin
Two other names are mentioned in Substack's extremist ecosystem is flourishing as evidence of not just a toleration but a possible favorable feeling toward white supremacist sympathizers. Marc Andreessen and Curtis Yarvin are some names of which you may have heard. Yarvin is currently near the top of Substack's bestselling writers in the category of History. This Yarvin, who has inspired many on the far right, wants to end democracy in favor of a monarchy headed by a technology CEO.
Then there is Marc Andreessen, a person I sometimes mix up with the other famous tech Marc (Zuckerberg of Facebook). Andreessen, who turns out was one of the founders of Netscape and Mosaic, ancient technology now but very big in the 1990s when I worked at Microsoft. Mosaic was the first visual interface for what we called the end user to view the world wide web; it was the first web browser. But come to find out that this Netscape guy is now part of the technology oligarchs who are helping to usher in the frightening world I do not want to see. Andreessen-Horowitz, a Privately Held Venture Capital firm is in fact a primary source of that recent one hundred million to Substack.
At the end of Substack's extremist ecosystem is flourishing, Katz and Kabas write: "As Silicon Valley swings right, a shift led in part by major Substack investor Marc Andreessen, Substack will only expand its role as a clearinghouse for the far-right, funded and legitimized by the non-fascists who remain on the platform." They point to an article by Alejandra Caraballo of The Dissident, 15 Jul 2025, The Techno-Fascist Soul of Marc Andreessen
Tolerance for Differences, Our American Civil Liberties
I find others are concerned about what appears to be Nazi-aligned, white supremacist content on Substack, a very useful platform for many. A New Zealand writer, David Farrier, recently moved from Substack to Ghost, explaining on August 15, 2025 Why Webworm Is Leaving Substack.
On Ghost, Farrier has more to say, including this part which helps me understand the difference between allowing free speech and not making a welcome home for it. On August 25, Farrier's Some More Thoughts on Substack mentions a conversation he had where the point is made that allowing Nazi content on a privately owned platform, allowing such authors to make money, is a choice made by the owners and funders of that platform. Nazi content authors are free to host and fund their own websites, but Substack is said to be a privately held company. Nazi sympathizers can and maybe already do pay to use the Ghost platform – I've not delved into that yet. Ferrier ends with saying that since the code for Ghost is open source, he can use it to self host.
The open source nature of Ghost makes me feel confident. I am paying them for hosting at the moment, but if they start supporting Nazis in a big way, I can take that Ghost code, and self host. - David Ferrier
I am not a programmer and certainly do not want to self-host, have no interest in how that works anymore. I would just have to pay for a programmer to do that part for me, if it came to that. But that is what Ghost offers, what I pay my $15 a month for. Exactly how hate speech and content is monitored and controlled on the Ghost-managed paid platform is a topic for another day.
About the Ghost platform wikipedia says: "The Ghost project is managed by a nonprofit organization headquartered in Singapore called the Ghost Foundation ...Ghost is free to download and use. In addition, the Foundation offers a paid platform for users who prefer a managed solution, as an alternative to self-hosting. For a monthly fee, users can build a Ghost website or blog..."
I would much rather be writing about the benefits of moss in one's yard, and the power of succulents to weather the elements, to be a great groundcover along with the moss. I would much rather be explaining the benefits of salmonberry and snowberry in a residential backyard than dealing with push notifications, self-hosting websites, and content moderation rules.
But times keep being what they are, so here we are for now.