WooYun

The WooYun, was a Mainland China-based vulnerability reporting platform founded in May 2010 by Fang Xiaodun and Meng De. It posted an announcement on July 20, 2016 that the site was down for an upgrade and would be restored in the shortest possible time. However, as of April 12, 2021, the website still remains inaccessible.
WooYun touted itself as a "free and equal platform for reporting vulnerabilities". The Wooyun.org domain name was registered on May 6, 2010.
Shut down.
On the evening of July 19, 2016, someone broke the news that all the senior managements of WooYun were taken away by the police.
"The Wall Street Journal" said it was unclear whether the Chinese government shut it down or its organizers did.
"iThome.com.tw" speculated that the most likely reason for the shutdown of WooYun was that hackers on the platform exposed a vulnerability in the system of China's United Front Work Department, which had leaked Chinese state secrets and stepped on the bottom line of the Chinese government.