Personal data leaked through unauthorized access has reached a cumulative total of about 260 million records since April, according to figures compiled by the government's Personal Information Protection Commission.
The commission published the figure as a preliminary estimate. The source does not break the total down by company, sector or type of data, and does not say how many separate breaches it covers.
The scale reflects a run of disclosures. On Thursday alone, email delivery company Arara said unauthorized access had leaked 3 million email addresses, and Life Card said the email addresses and other data of more than 330,000 customers may have been exposed. A company selling figures said credit card details for 2,800 people may have leaked, and Matsuya Foods stopped its website and app after detecting unauthorized access.
GMO, which has also been hit, said it had obtained strong information that could lead to identifying the attackers and submitted it to police and other authorities.
Leaked data is also being used for secondary fraud. Card misuse following personal data leaks has been reported, with the methods used to exploit the information evolving.