JD Sports has warned that around 10 million people might have had their personal data stolen after it was hit by a cyber attack.
The sports retailer said the affected brands from the group are JD, Size?, Millets, Blacks, Scotts and Millet Sport.
However, even with the attack the JD group has said payment card details were "safe" and that it has no reason to think the hackers have accessed users' passwords.