Nicknamed "Big Cannon Ren", he is known for his outspoken views on Sina Weibo, where he accumulated more than 37 million followers until it was deleted by the Chinese authorities in 2016.

[1][2] He disappeared on 12 March 2020 after criticizing CCP general secretary Xi Jinping as a "clown" over the handling of China's response to the COVID-19 pandemic.

His father, Ren Quansheng (任泉生; 1918–2007), served as China's Vice Minister of Commerce, and his mother was a municipal official in Beijing.

According to his long-time colleague, the reason for his imprisonment was because he had offended the head of the audit department of Beijing's Xicheng District.

"[14] The tweet was subsequently deleted, but on 22 February 2016, state-affiliated media accused Ren of advocating the overthrow of the Communist Party.

[3][4] He said that the lack of free press and freedom of speech had delayed the official response to the pandemic, worsening its impact.

[21] On 22 September 2020, after a one-day trial, a Chinese court found Ren guilty and sentenced him to prison for 18 years for corruption, bribery, and the misuse of public funds, claiming that he did not contest the charges.

[22][23] On 4 October 2024, Ren's daughter, Ren Xinyi, published an open letter to Xi Jinping on WeChat urging him to release her father on compassionate grounds, citing his deteriorating health conditions due to a serious prostate ailment and worsening asthma.