Security flaw could have been used to discover the country code of peoples phone numbers if they had one associated with their Twitter account, as well as whether or not their account had been locked by Twitter. Twitter is investigating the possibility that the flaw may have been abused by potential nation-state actors, particularly from IP addresses associated with Saudi Arabia and China. Security researcher who goes by @Fawaz Ahmad Qureshi has stepped forward to disclose that he had reported the flaw to Twitter via HackerOne more than two years ago.”]