DuelingNetwork

Dueling Network was a popular web-based Flash game centered on the Yu-Gi-Oh card game ecosystem. Although the main game service was discontinued in 2016 due to legal issues, the associated community forum remained operational for another year. In March 2017, the forum database was compromised and leaked online. The breach exposed sensitive user data including account usernames, email addresses, IP addresses, and passwords stored as saltless MD5 hashes, making them highly vulnerable to cracking. The incident impacted approximately 2.5 million users who had registered for the platform during its operation.