The number of people affected or the largest group of victims is uncertain. Some of them were probably in the European Union because Microsoft provides contact information for its data protection officer. Business customers were not involved either. The technology company's messaging offers include everything from modern Outlook.com accounts to old Hotmail and MSN addresses.
It is unlikely to be as serious as the violation that has affected more than 772 million e-mail addresses, but this remains a substantial breach of privacy. The attackers could theoretically use it not only for junk mail, but also to gather detailed information about the personal lives of their users and to put off the fraud and theft of identity.