After months of waffling, lawsuits, verbal mudslinging and the near miss of a full blown trial, Elon Musk now owns Twitter. On Thursday night, Mr. Musk closed his $44 billion deal to buy the social media service, said three people with knowledge of the situation. He also began cleaning house, with at least four top Twitter executives — including the chief executive and chief financial officer — getting fired on Thursday. Mr. Musk had arrived at Twitter’s San Francisco headquarters on Wednesday and met with engineers and ad executives.
The closing of the deal, which followed months of drama and legal challenges as Mr. Musk changed his mind about buying the company, sets Twitter on an uncertain course. Mr. Musk, a self-described “free speech absolutist,” has said that he wants to make the social media platform a more freewheeling place for all types of commentary and that he would “reverse the permanent ban” of former President Donald J. Trump from the service.
Mr. Musk’s open approach to speech on Twitter could exacerbate long simmering issues of toxic content and misinformation, affecting political debates around the world. Early tests will come within days, when Brazil elects its president and American voters go to the polls on Nov. 8 for the midterm elections. Twitter said it would prohibit misleading claims about voting and the outcome of elections, but that was before Mr. Musk owned it.

“There could be real-world consequences to his leadership,” David Kaye, a law professor at the University of California, Irvine, who worked with the United Nations on issues of free speech, said of Mr. Musk’s ownership of Twitter. “To the extent that world leaders see they have this space and it’s unmoderated, they could push to see how far they can go.”
Mr. Musk, 51, will be remaking Twitter without having to disclose how it is performing every few months. By taking the company private, he does not need to regularly answer to shareholders and can make changes to the service away from the public’s prying eyes. Mr. Musk, who also runs the electric carmaker Tesla and the rocket company SpaceX, did not immediately respond to a request for comment. Completing the deal was a victory for Twitter’s board. When Mr. Musk agreed to pay $54.20 a share for the company in April, Twitter faced criticism for accepting a price that was too low. But, as the global economy faltered in the ensuing months and Twitter’s stock fell, the deal price appeared to be a win for shareholders, and the board sought to force Mr. Musk to abide by the agreement. A Twitter spokesman did not immediately respond to a request for comment. The Twitter executives who were fired on Thursday include Parag Agrawal, the chief executive; Ned Segal, the chief financial officer; Vijaya Gadde, the top legal and policy executive; and Sean Edgett, the general counsel, said two people with knowledge of the matter. At least one of the executives who was fired was escorted out of Twitter’s office, they said. Mr. Musk, who is one of Twitter’s most active users and has more than 109 million followers, began accumulating shares in the company this year. In April, he struck the deal to buy the company for $44 billion and said he would lift Twitter’s content moderation policies, eliminate spam, add new features and provide more transparency about the algorithms used to promote content. “Twitter has tremendous potential — I look forward to working with the company and the community of users to unlock it,” he said in a statement in April. But, within weeks, he began questioning the deal. Mr. Musk lashed out at the Twitter executives responsible for content decisions and accused the company of failing to accurately count the spam accounts on its platform. When Parag Agrawal, Twitter’s chief executive, tried debunking Mr. Musk’s claims, Mr. Musk responded by tweeting a poop emoji.