- Japanese energy giant reveals it lost a drive containing data from millions of customers
- The unit was left in an apparently open cabinet
- Almost 11 million customers at risk, but no bank or card details were affected
A Japanese energy giant has apologized after losing a physical storage drive containing data from millions of its customers.
Workers at Kyushu Electric Power Co. apparently misplaced the unit, which had been left in an unlocked cabinet, the company said in an official announcement.
The drive allegedly contained information on up to 10.9 million accounts, including customer names, electricity usage data and phone numbers, although the company said no bank account information or credit card data was stored.
Absence without leave
Kyushu Electric Power Company, one of Japan’s largest regional utilities, supplies electricity to the entire Kyushu region, which has a total population of around 12.5 million people and includes major prefectures such as Fukuoka, Nagasaki, Kumamoto and Kagoshima.
In its announcement, the company explains that IT staff regularly perform backups to manage server storage.
He added that due to capacity limitations, an external storage device was used for the task on April 27, 2026.
This drive was then stored in a server room cabinet protected by multiple layers of physical security, a location to which only 57 people had access.
However, when IT staff went to retrieve the drive on May 26, they discovered that the enclosure had been left open and the controller was missing.
Kyushu Electric filed a police report on June 4 and the company says it has since conducted its own investigations, including interviewing all staff who entered the server room, but the unit cannot be found.
“The company is investigating all possibilities, including unauthorized removal of the device, but it has not yet been located,” the announcement states.
The incident has now been reported to Japan’s Personal Information Protection Commission and relevant government authorities, and Japan’s Ministry of Economy, Trade and Industry reportedly gave Kyushu Electric until July 8, 2026 to report full details about the incident and preventive measures taken.
Through ringing computer
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