Todd Spangler NY Digital EditorA new study estimates that upwards of 10% of Twitter active accounts post spam content — double the company’s own claims.The report from U.K.-based data analytics and consulting firm GlobalData comes as Elon Musk, the billionaire Twitter power-user, has threatened to nix his $44 billion deal for the social network over the question of the prevalence of spam and fake accounts on Twitter. On Monday, Musk’s lawyers sent a letter to Twitter alleging the company was in “clear material breach” of the acquisition agreement because Twitter has refused to furnish information backing up its claim that fake/spam accounts represent less than 5% of daily active users.A Twitter rep declined to comment.