Twitter is also banning promotions of third-party social media link aggregators such as Linktree, which some people use to show where they can be found on different websites.

Twitter users will no longer be able to link to certain rival social media websites, including what the company described Sunday as “prohibited platforms” Facebook, Instagram and Mastodon.

It's the latest move by Twitter's new owner Elon Musk to crack down on certain speech after he shut down a Twitter account last week that was tracking the flights of his private jet.

“We know that many of our users may be active on other social media platforms; however, going forward, Twitter will no longer allow free promotion of specific social media platforms on Twitter,” the company said in a statement.

The banned platforms include mainstream websites such as Facebook and Instagram, and upstart rivals Mastodon, Tribel, Nostr, Post and former President Donald Trump's Truth Social.

Twitter gave no explanation for why the blacklist included those seven websites but not others such as Parler, TikTok or LinkedIn.

Twitter is also banning promotions of third-party social media link aggregators such as Linktree, which some people use to show where they can be found on different websites.

Twitter previously took action against one of the rivals, Mastodon, after its main Twitter account tweeted about the @ElonJet controversy last week.