Update, 9:00 pm Pacific
The tweets announcing the policy change are gone, as is the policy. (I have screen captures.) Mastodon.social links remain blocked as malware, with no explanation.
Update, 4:25 pm Pacific
Links to Facebook, Instagram and TruthSocial have not been blocked. Only Mastodon (which started Friday, unannounced).
Sunday morning, Twitter Support announced a change in corporate policy on outbound content links or shared profile links to some competing digital networks.
However, Twitter began blocking links to Mastodon.social on Friday, before announcing this policy.

I started a Twitter thread to share amusing responses and then discovered this (notice the lack of a date; emphasis added):
December 2022
Twitter is where the public conversation is happening, and where people from all over the globe come to promote their businesses, art, ideas, and more. 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.What is a violation of this policy?
At both the Tweet level and the account level, we will remove any free promotion of prohibited 3rd-party social media platforms, such as linking out (i.e. using URLs) to any of the below platforms on Twitter, or providing your handle without a URL:
- Prohibited platforms:
- Facebook, Instagram, Mastodon, Truth Social, Tribel, Post and Nostr
- 3rd-party social media link aggregators such as linktr.ee, lnk.bio
- Examples:
- “follow me @username on Instagram”
- “username@mastodon.social”
- “check out my profile on Facebook – facebook.com/username”
Accounts that are used for the main purpose of promoting content on another social platform may be suspended. Additionally, any attempts to bypass restrictions on external links to the above prohibited social media platforms through technical or non-technical means (e.g. URL cloaking, plaintext obfuscation) is in violation of this policy. This includes, but is not limited to, spelling out “dot” for social media platforms that use “.” in the names to avoid URL creation, or sharing screenshots of your handle on a prohibited social media platform.
- Example: “instagram dot com/username”
[…]
What happens if you violate this policy?
Tweet deletion and temporary account locks
- If violations of this policy are an isolated incident or first offense, we may take a number of actions ranging from requiring deletion of one or more Tweets to temporarily locking account(s). Any subsequent offenses will result in permanent suspension.
Temporary suspension
- If violations of this policy are included in your bio and/or account name, we will temporarily suspend your account and require changes to your profile to no longer be in violation. Subsequent violations may result in permanent suspension
When I attempted to tweet a nine-tweet thread about this policy change, Twitter posted the first two and sent the other seven to the bit bucket.
https://twitter.com/kegill/status/1604576663609970688
I pointed out that the emperor has no clothes:

@elonmusk, 05 June 2022
I outlined the information above warning suspensions are in the works for bios (like mine) that contain links to unfavored competition, including linktr.ee (really?).
I included some great jabs!
If you’re driving a Tesla and happen to say “Prius,” do you smash into a wall?
— Bill Grueskin (@BGrueskin) December 18, 2022
And the fact that Elon has violated European laws.
IMPORTANT: @elonmusk's new policy preventing linking to competitors is in DIRECT VIOLATION of European Union rules.
Penalty can be a fine of up to 20% of Twitter's annual revenuehttps://t.co/Wu1dU4JRn7 pic.twitter.com/cZWsl92npr
— Judd Legum (@JuddLegum) December 18, 2022
Things do not look good at the BirdSite.
I tested TruthSocial, Facebook and Instagram. Guess what.Each outbound link worked.
Despite @TwitterSupport claiming that Truth Social (their spelling) was also blocked, it’s not. https://t.co/XGpEBf69oo
— 🇺🇦Kathy E Gill | mastodon.social/@kegill (@kegill) December 19, 2022
Facebook links to page and profile also work. Ditto Post.News.
Here’s an Instagram post that makes fun of Elon. Will I be able to share it? Bets?https://t.co/AhnIZuXeaN
— 🇺🇦Kathy E Gill | mastodon.social/@kegill (@kegill) December 19, 2022
Find me at mastodon.social/@kegill | post.news/kegill
Header image by the author. CC attribution.