In this article on baidu, there is a gap between 1988 and 1999, why is there nothing about some kind of protest that everyone keeps telling me about?

Edit: Thank you for responding, you have taught me a great deal about the usage and necessity of propaganda, counter-propaganda and censorship in a Marxist-Leninist state like China. Although some relied upon lies and insults as a means of trying to win an argunent, I got actual contentful theoretical education out of this, thanks.