Twitter has started marking links to Substack as unsafe. If you click on a link on Twitter with substack.com in the URL, Twitter will show a separate notice warning you that “the link you are trying to access has been identified by Twitter or our partners as being potentially spammy or unsafe.”
Don’t be alarmed — the links we’ve checked appear to be perfectly safe. This notice seems instead to be Twitter’s latest hostile move toward Substack after the email newsletter platform announced its own Twitter-like “Notes” feature on Wednesday.
On Thursday, Twitter blocked people who use Substack from embedding tweets into their stories. Then, late Thursday or early Friday, Twitter started blocking engagement on tweets containing links to…