Twitter appeared to pause sign-ups for its subscription service, Twitter Blue, early Friday morning after a trolling blitz by people who used the service’s new “verified” checkmark to impersonate famous people and companies. Twitter entered a state of tumult two weeks ago, when new Elon Musk bought the company, fired staff en masse, and proposed sweeping new changes to the way Twitter authenticates notable accounts. One of Musk’s first changes as CEO was to expand the subscription “Twitter Blue” service, so that any subscribers to the $7.99-per-month service would receive a blue “verified” checkmark. But questions lingered about the new system, especially after it became clear that Twitter was not taking any steps to authenticate the ownership behind new “verified” accounts. Impersonators quickly purchased the new blue checks to pose as companies and public figures like Tesla, Rudy Giuliani, the Pope, and pharmaceutical giant Eli Lilly. On Thursday night, Musk tweeted that “going forward, accounts engaged in parody must include ‘parody’ in their name, not just in bio.” By Friday morning, Twitter appeared to have suspended its Blue program, removing a “Twitter Blue” button from its app and barring new sign-ups, users reported. It also reactivated its gray “official” checkmarks, a new feature it had launched and almost immediately rescinded on Wednesday.