The disinformation emerging from Twitter is nearly as bad as the disinformation its new owner, Elon Musk, says he wants to contain. He should start by getting a mirror into his fancy office. It didn’t start well. The dad joke of bringing a sink to the office (let the message “sink” in, har-de-har), firing a tranche of top executives, threatening thousands more, and then tweeting ghastly rumours about the appalling attack on Paul Pelosi, husband of US House Speaker Nancy, before hastily deleting it. Musk ended up ditching the board and appointing himself as CEO of possibly the planet’s most...