I’m hardly following any very well-known people on any social media – but I was positively surprised to see Tim Berners-Lee (@timbl@w3c.social) on Mastodon! Well for the unlikely event that you don’t know what we owe him, check out his Wikipedia entry:
Sir Timothy John Berners-Lee (born 8 June 1955),[1] also known as TimBL, is an English computer scientist best known as the inventor of the World Wide Web, the HTML markup language, the URL system, and HTTP.