Troy Hunt, creator of breach-notification site Have I Been Pwned, viewed the leaked data and said on Twitter that it seemed "pretty much what it's been described as." There were no clues to the identity or location of the hacker or hackers behind the breach. It may have taken place as early as 2021, which was before Elon Musk took over ownership of the company last year. Claims about the size and scope of the breach initially varied with early accounts in December saying 400 million email addresses and phone numbers were stolen. A major breach at Twitter may interest regulators on both sides of the Atlantic. The Data Protection Commission in Ireland, where Twitter has its European headquarters, and the U.S. Federal Trade Commission have been monitoring the Elon Musk-owned company for compliance with European data protection rules and a U.S. consent order respectively.