Nintendo has confirmed that up to 160,000 user accounts have been compromised, with user nicknames, regions, email addresses and dates of birth being exposed.
Some unauthorised payments have also been made on affected accounts, though Nintendo has confirmed that credit/debit card information has NOT been accessed.
A spokesman for Dorset Police's Cyber Crime Unit said: "If you have a Nintendo Online account, take the time to check your sign in history.
"If there is anything there that you do not recognise, change your password as soon as you can.
"Nintendo Online also allows the use of Two Factor Authentication, which we strongly recommend implementing if you haven't already.
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