Twitter’s board of directors accepted Elon Musk’s offer to buy the social network for $54.2 a share in a $44 billion deal. One consequence will be that Twitter will be a private company again leaving the Wall Street Stock Exchange. In early April, Musk bought 9.2% of the social network but decided not to join its board. Now, his stated goal is to change Twitter to ensure free speech, which he sees as a bedrock of democracy.