According to Pres. Donald Trump, and other Conservative leaders, social media platforms like Twitter engage in "shadow banning" which means making it hard to find postings by Conservatives. The issue is being raised repeatedly, especially in the last couple days with a twitter tirade by Pres. Trump. Therefore it is rich in irony that Rep. Kevin McCarthy posted a series of tweets last week complaining about this, ending with supposed PROOF of Twitter shadow banning. Except ... it was due to his account settings.
The tweet Rep. McCarthy referenced, from Fox "news" host Laura Ingraham, was shown to McCarthy as "This tweet is not available because it includes sensitive content".
Technically that behavior, if this were imposed by Twitter, is not shadow banning. In shadow banning, nobody knows the person has been shadow-banned: Instead they use the platform as always, but other users have a hard time finding that user's content. In this case McCarthy saw the content, but it was blocked from being seen.
Why was Ingraham's tweet blocked from being seen? It was due to settings on McCarthy's Twitter account. Twitter did not take any action other than to respond to a setting on McCarthy's account.