22 million user IDs may have been stolen during an unauthorised attempt to access the system. The information did not include passwords and the kind of data necessary to verify a user’s identity or reset passwords, the company said. In 2011, Sony said information such as usernames, passwords and birth dates of more than 100 million people were compromised after hackers struck the PlayStation Network and Sony Online Entertainment services. Japan acknowledges that its preventative measures against cyberattacks remain underdeveloped, with the national police agency having announced this month it would launch a team to combat the problem.
Source: https://thehackernews.com/2013/05/22-million-yahoo-ids-stolen-from-its.html