2026-11-15
Cyberattack on the Yomiuri Giants fan club CLUB GIANTS: 807,030 member email addresses leaked — what members should do
On November 13, 2026, the Yomiuri Giants announced that the system managing member information for its official fan club, CLUB GIANTS, was hit by an external cyberattack and that 807,030 member email addresses leaked. The attack began around 3:00 a.m. on November 12, the addresses leaked by around 9:00 a.m., and the count was established at 1:00 p.m. on November 13. The club says it does not hold credit card information in that system, so it is not affected, and it has received no reports of misuse so far. It is still investigating whether anything other than email addresses leaked. The attack has been blocked, and the club reported the matter to the Personal Information Protection Commission on November 13. It plans to contact affected members individually by email and other means. It warns that suspicious emails pretending to come from the club or related parties may be sent, and asks people not to open URLs or attachments in them. Our conclusion: what leaked is email addresses, which makes fake messages in the name of the Giants or the fan club look convincing, so do not open links in such messages and check through the official site or app instead.