renren.com

In 2014, the Chinese social networking site Renren was compromised, exposing the personal information of over 4.6 million users. The leaked data included names, email addresses, phone numbers, and even plaintext passwords.

The breach was discovered by security researcher Bob Diachenko, who found the leaked data on an open server. Diachenko then notified Renren about the breach, who quickly took steps to patch the vulnerability and notify affected users.

The Renren leak was one of the largest data breaches in Chinese history, and it highlighted the importance of data security. In the wake of the breach, Renren implemented new security measures to protect user data, and the Chinese government also tightened regulations on data protection.