Kotaku reports that Nintendo's member rewards site Club Nintendo was recently hacked, exposing Japanese members' personal information.
According to a statement on the company's Japanese Web site, 15,457,485 attempted logins resulted in 23,926 successful unauthorized logins between June 9 and July 4, 2013.
Customer data that may have been accessed includes names, addresses, phone numbers and e-mail addresses. No credit card information was exposed.
Following the breach, according to Kotaku's Brian Ashcraft, Nintendo is strengthening its security and has reset all Club Nintendo members' passwords.