About 2.58 million So-net and docomo Hikari plala customer records were exposed in an October 2026 hack of Sony Network Communications, Sony’s internet service provider in Japan. No lawsuit or compensation has been announced, and there is nothing to claim.
What Happened?
Sony Network Communications, the Sony Group company that runs the So-net internet service in Japan, said on October 27, 2026, that an outside party broke into its So-net member database on Monday, October 19. The company says it confirmed the access on October 23, shut down the affected server and cut off traffic from the source. A day later, its investigation found that personal information had been taken.The notice lists 2,141,986 So-net member records and 443,495 records for plala (S Course), the docomo Hikari internet plan that NTT Docomo pays Sony Network Communications to run. That is 2,585,481 records in all, the figure news reports have rounded to 2.5 or 2.6 million. Sony counts records, not people, and has not said how many individuals are behind them.
Sony has not said how the attackers got in. Its notice describes the cause as unauthorized access by a third party that is still under investigation, and says the company has reported the incident to Japan’s Personal Information Protection Commission.
Free settlement alerts
Get notified when new class actions open to claims
Join thousands of readers who get the latest class action settlements you may qualify for — delivered straight to your inbox.
What Information Was Exposed?
Sony’s notice breaks the leak into five groups:- So-net members: 1,869,771 current members and 272,215 former members who canceled in March 2026 or later. The exposed fields are name, phone number, email address, user ID, date of birth, gender and internet connection ID. Sony says member passwords were not leaked.
- So-net email accounts: 54,401 email addresses together with their email passwords, on four services: Mail Service (G) (24,655), the paid A-Box extra mailbox (17,672), So-net VAIO Mail (7,005) and PostPet Mail Account Service (5,069).
- plala (S Course) customers: 422,365 current customers and 21,130 who canceled in March 2026 or later, with the same fields as So-net members and no passwords.
- Bank accounts: 16 records showing the bank, branch, account type, account number and account holder name. Sony says it does not hold account PINs and that no plala customer was in this group.
- Password-reset letters: details from 7 notices Sony issues to reset passwords. Sony reset those passwords.
Some early reports disagreed on passwords and bank data. Sony’s own notice settles both points: login passwords for So-net and plala memberships were not taken, the 54,401 email passwords were, and 16 bank account records were exposed.
Who Is Affected?
The records belong to customers of internet services sold in Japan. NTT Docomo’s own notice says the plala exposure covers current docomo Hikari plala (S Course) subscribers and those who canceled within the past six months. Other plala plans, including plala (docomo Hikari) and Plala Hikari Mate with FLET’S, were not affected.Sony says it found no leak from NURO, its fiber service, or from any other service beyond those listed. Sony Network Communications is a separate company from Sony Interactive Entertainment, which runs PlayStation Network, and the notice does not mention PlayStation accounts.
Sony says it will contact affected customers individually.
What Sony Is Telling Customers
Sony reset the 54,401 exposed email passwords on October 27. The notice says those customers have to set a new password through the So-net My Page site.As of October 27, both Sony and NTT Docomo said they had found no misuse of the data. Both warned that the stolen names, phone numbers and email addresses could be used in scam emails, texts and calls. Their notices urge customers not to respond to suspicious messages and not to open links or attachments in them. Sony also says it is reviewing its security and information-management practices.
Is There a Lawsuit?
No lawsuit had been reported as of October 29, 2026, and Sony has not announced compensation for affected customers.In the United States, a breach of this size usually draws proposed class actions within days. The affected customers here are subscribers of Japanese internet services, though, and Japan has no U.S.-style opt-out class action. Under Japan’s collective redress system, only consumer organizations certified by the government can bring a group damages case.
Sony has faced U.S. class actions over earlier breaches. Both the 2011 PlayStation Network breach and the 2014 Sony Pictures hack led to lawsuits that ended in settlements. OCA will update this page if a case is filed over the So-net breach. Open data breach settlements in the U.S. are listed on the data breach settlements page.
Questions
Were Sony PlayStation or other Sony accounts affected?
Sony Network Communications’ notice covers only So-net member records, four So-net email services and docomo Hikari plala (S Course) customers. It says no leak was confirmed for NURO or any other service. The notice does not mention PlayStation Network, which is run by a different Sony company.
Were passwords stolen in the Sony So-net breach?
Sony says So-net and plala member login passwords were not leaked. Email passwords were taken for 54,401 addresses on four So-net mail services: Mail Service (G), A-Box, So-net VAIO Mail and PostPet Mail Account Service. Sony reset those passwords on October 27, 2026, and their owners have to set new ones through So-net’s My Page.
Is there a class action over the Sony So-net data breach?
No lawsuit had been reported as of October 29, 2026, and Sony has not announced any compensation. The affected customers are subscribers of Japanese internet services, and Japan has no U.S.-style opt-out class action. Its collective redress procedure can be brought only by government-certified consumer organizations.
Is the Sony So-net breach the same as the 2.5 million record breach in the headlines?
Yes. News reports round the total to 2.5 or 2.6 million. Sony’s notice lists 2,141,986 So-net member records and 443,495 plala (S Course) records, or 2,585,481 in all. Those are customer records, and Sony has not given a count of unique people.
Sources
• Sony Network Communications: Notice of So-net Member Database Breach (October 27, 2026, Japanese)• NTT Docomo: Notice to docomo Hikari plala (S Course) Customers (October 27, 2026, Japanese)
• BleepingComputer: Sony ISP Subsidiary Data Breach Exposes 2.5 Million Customer Records
