What Happened
In December 2011, Tianya Club (Tianya.cn), China’s largest online forum at the time, suffered a major data breach when hackers infiltrated its systems, exposing sensitive information from tens of millions of user accounts—primarily those registered before November 2009—including usernames, email addresses, and clear-text passwords. The incident affected approximately 31.2 million records (with 28.7 million unique emails and over 12.9 million unique passwords), though some reports cited up to 40 million users, compromising around 60% of the site’s user base and leading to widespread account takeovers on other platforms due to password reuse. Tianya confirmed the leak, urged users to change passwords, reported it to police, and noted that post-2010 upgrades had encrypted newer passwords, but the dumped data quickly circulated online, marking one of China’s most significant breaches.
