14.6.3. Hundred Flowers Campaign 百花齐放 (1956-1957)

Some possible quotes from Mao saying that people should be able to protest, original share: https://www.reddit.com/r/China/comments/i2z5ss/maos_propaganda_poster_saying_protest_and_strike/

允许群众示威。
Citizens should be allowed to protest.

claims from from some 毛泽东选集第五卷 (selected works from Mao Zedong) in speech from the 8th Central Committee of the Communist Party of China. https://twitter.com/shijianxingzou/status/1158421996755128323 mentions the anthology was published in 1977.

Liu Shihui (刘士辉) also comes to mind.