SOCIAL MEDIA platform X, formerly known as Twitter, could introduce a monthly fee for all users, its owner Elon Musk has said. The tech tycoon has made multiple changes since taking over the site for $44 billion in October last year. He has fired thousands of employees, introduced a paid premium option, cut content moderation and reinstated formerly banned accounts including that of former US president Donald Trump. He said in July the platform had lost roughly half its advertising revenue. Bots – accounts run by computer programs rather than humans – are common on X, where they can be...