Remember that Trump guy who was President of the US for a while? A while ago he wanted to start his "own" social network but he seriously copied the code of Mastodon and removed all backlinks so it looked like it was "custom made".
Luckily he failed very hard and people discovered it was Mastodon! So he had to publish the source code according to the Mastodon licence
Now it seems he's not even using it and he will prob return to Twitter. Talk about a fail!