So much for “free speech absolutism.”

Twitter is censoring Substack links by making the posts impossible to reply to, like or retweet. While quote-tweeting works, simply pressing the retweet button surfaces an error message: “Some actions on this Tweet have been disabled by Twitter.”

The timing of this action doesn’t seem coincidental. Two days ago, Substack launched its Notes feature, which looks a whole lot like Twitter. Unlike other new Twitter alternatives, Substack has a huge advantage: people actually use the platform, and many writers already have massive followings there. Such writers include Matt Taibbi and Bari Weiss, who Twitter owner Elon Musk partnered with to publish “The Twitter Files.”

Under Musk’s ownership, Twitter has also taken steps to suppress content from Mastodon, an open source social network that gained a sudden influx of users when Musk took control of Twitter. In December, Twitter temporarily suspended Mastodon’s account and banned posting links to Mastodon servers. On its formerly banned Twitter account, Mastodon said, “Not a good sign if you need to build a wall to keep people in.”

“We’re disappointed that Twitter has chosen to restrict writers’ ability to share their work. Writers deserve the freedom to share links to Substack or anywhere else,” Substack’s founders wrote in an emailed statement. “Their livelihoods should not be tied to platforms where they don’t own their relationship with their audience, and where the rules can change on a whim.”

Musk is an active critic of mainstream media, going as far as slapping a misleading “state-affiliated media” label on NPR’s account. These labels are usually reserved for publications that do not have editorial independence from state government, but the government has no hand in NPR’s content; plus, the news organization only received about 1% of its budget from federal funding in 2020.

Substack is touted as an alternative to mainstream media, giving writers a platform to earn subscription revenue with very little editorial regulation. Similar to Musk’s own views on content moderation, Substack takes a “hands-off” approach — the newsletter site has even come under fire for choosing not to intervene when writers spread misinformation about vaccines.

Anyway, you didn’t hear this from us, but if you link to a Substack via a redirected URL, it seems to post without restrictions.