Any of the people/journalists that were reporting on the inner workings of Twitter that Musk didn't like so he shut it down would be something that jumps to mind.

Musk very clearly actively sticks his fingers in the pie to steer narratives. Easy example, one of his children came out as trans (to Elon's apparent dismay), and now "cisgender" is flagged as a slur/hate-speech. There is other, anecdotal evidence that certain posters (ridiculously, Musk included) have their posts elevated above baseline visibility, but I don't have any statistics to back that up. Other flavorful unsolicited changes to the platform, such as changing blocking to allow blocked people to still see your posts, seem again like self-serving dictates from the top. Perhaps generally not censorship, but heavily biased moderation very clearly steered by the agenda of a single man.

Several. Consider ElonJet as a silly but representative example of where the limits of free speech are considered for the far right.

Hate speech and harassment is totally fine, but not critique.

[0] https://en.wikipedia.org/wiki/ElonJet