- A 15-year-old boy in Japan was arrested for using artificial intelligence to delete tens of thousands of accounts on an anime streaming service, causing a month-long service suspension.
- The high school student from Tokorozawa admitted to writing the source code himself before turning to ChatGPT to refine and complete it, targeting the company because there were many accounts he could log into.
- Bandai Namco Filmworks announced that personal information from up to 1.36 million accounts, including email addresses and payment methods, had potentially been leaked, leading to the company issuing refunds and taking measures to prevent recurrence.
A 15-year-old boy in Japan has been arrested for using artificial intelligence to help him build a programme that forcibly deleted tens of thousands of accounts on an anime streaming service
Police described the incident as a deliberate and persistent cyberattack that forced a month-long service suspension
The high school student from Tokorozawa, near Tokyo, was accused of fraudulent obstruction of business after sending false commands to the servers of Bandai Namco Filmworks, a subsidiary of Japan’s largest toymaker Bandai Namco Holdings, on 4 November 2025
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The attack triggered the mass de-registration of 46,812 accounts on the company’s Bandai Channel streaming service without the knowledge or consent of those users, Tokyo’s Metropolitan Police Department said
The student admitted to the allegations, telling investigators he had written the initiale it
“I created the was taking a long time, I asked ChatGPT and completed it in a different programming language,” he told investigators, according to the Asahi Shimbun
He said he held no grudge against the company, explaining that he had targeted it simply because there were many accounts he could log into
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Even after Bandai Namco Filmworks took countermeasures and blocked his access, the student allegedly changed his IP address 30 times to continue sending the false commands
The company was forced to suspend services for more than a month and issue refunds to affected members
The following month, Bandai Namco Filmworks announced that personal information from up to 1.36 million accounts, including email addresses, account balances and payment methods, had potentially been leaked
The company said no secondary damage, such as data being published online, had been confirmed
“We take this situation very seriously and will continue to conduct regular checks and strive to prevent any recurrence,” it said
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The student had taught himself to code as an elementary school pupil and told investigators he enjoyed analysing network communications
He had already been arrested in June on suspicion of logging into the streaming service using another member’s account, which led investigators to uncover the wider attack
A senior Metropolitan Police Department investigator issued a warning following the arrest
“Cyberspace is highly anonymous, and people may be tempted to commit crimes casually, but these actions can lead to grave consequences,” the investigator said
The case is among the first in Japan to involve the use of generative AI as a tool in a cyberattack, raising fresh questions about how easily such technology can lower the barrier for criminal activity online
