126.com

In approximately 2012 the Chinese email service provider 126.com owned by NetEase suffered a significant data breach affecting millions of subscribers. The incident involved the exposure of user credentials in an insecure manner. Cybersecurity researchers and databases later identified that the leak contained millions of unique email addresses paired with passwords stored in plain text format. This exposure posed a severe risk as it allowed unauthorized access to user accounts and potentially other linked services due to credential stuffing attacks.