Twitter is now warning against Mastodon servers as being unsafe, which is a de-facto blockade.
If you have the nerves, you select "Ignore this warning and continue" - But how can you be certain, that the particular Mastodon-instance really is out of harm?
The solution is simple: Make sure you do have your own security apps screening sites before visiting them.
Obviously you can no longer trust Twitter, which is a shame.
#mastodonmigration