The government-affiliated Japan Pension Service's computer system has been hacked, resulting in the leak of the names and pension ID numbers of 1.25 million pension premium contributors and pension recipients. In some cases, birthdates and addresses were also stolen. The leak is unprecedented among government organizations in terms of the number of people affected.

The government should take effective measures to prevent the stolen data from being misused for purposes such as pension fraud. In addition, the investigation committee set up following the revelation of the leak last week must determine how serious the government and the JPS were about security.

The hack occurred when JPS workers opened email attachments containing viruses. The first virus was detected on May 8 and the JPS reported the incident to the Health, Labor and Welfare Ministry. Another virus was detected on May 18 in 100 emails sent to the JPS. The next day, the JPS asked the Metropolitan Police Department to investigate. On May 28, the MPD told the pension organization that the pension data had been leaked. The JPS went public with the leak on June 1.