• It appears that posting links to Twitter's rival Mastodon is prohibited.
• An error warning appeared when Insider tried to publish tweets using Mastodon links.
• The tweet's content was labelled as 'possibly dangerous' in the error message.

Users of Twitter are no longer allowed to share some links to Mastodon, a social media competitor. Mastodon is organised into servers, or groups, based on a variety of topics, such as the UK, snooker, and security. Links to some of the biggest servers that users would join, including the most well-known 'social' channel, have been blocked by Twitter.

Additionally, Twitter is banning users from including links to their Mastodon accounts in their biographies since they are considered 'virus.' The claim that Mastodon contains malware, or dangerous software that can harm your device, is categorically unsupported by any evidence.

Hundreds of thousands of new users joined Mastodon in November, according to the social media network, as some Twitter users looked for substitutes. The most popular mastodon.docial server and more than 10 others, including a server for journalists and one for UK residents, are not accessible to the BBC.

There are workarounds, albeit not all links to Mastodon have been disabled. Because it is not a clickable link, Zoe Kleinman, the BBC's technology editor, was able to tweet a reference to her Mastodon account. It is unable to post the reference as a clickable link to her Mastodon profile afterward.

Neither the number nor the rationale behind Twitter's blocking of Mastodon servers is known. An error notice that reads: 'We can't complete this request because this link has been flagged by Twitter or our partners as being potentially hazardous' will be displayed to users who attempt to submit links to prohibited servers. Twitter has taken action against its competitor's main account in addition to restricting specific links to Mastodon.

On Thursday, a number of well-known journalists who were covering Twitter founder Elon Musk were also unexpectedly suspended, along with the Twitter account @joinmastodon, which promoted the website and its capabilities.

Due to this, the EU has threatened sanctions against Mr. Musk and warned that compliance with the EU's Digital Services Act requires respect for media freedom.