Maybe I interpret it wrong, but here is a tricky point: You have to apply for government's permission to do a legal on-street protest.
ref: http://www.npc.gov.cn/wxzl/gongbao/1989-10/31/content_148121... (Chapter 2 Article 7, Chinese)
ref: http://www.npc.gov.cn/wxzl/gongbao/1989-10/31/content_148121... (Chapter 2 Article 7, Chinese)
So I'm a little curious that if a protest is related to complaints about the government, will it get accepted (at most cases)?
Sometimes, municipalities still try to block protests because of politics/people they don't like participating, under the guise of some more neutral explanation (usually noise or safety). But judges generally take a dim view on such shenanigans, and they rarely pass scrutiny in the courtroom, since the government is then expected to explain the exact grounds for denial, and prove that it is relevant and narrowly tailored.