In China, censorship relates to red lines. You cannot cross some red lines. It’s about state policy and discussions (about) state power. It’s also related to what they would call minority or religious issues, which can be very sensitive, so people would not touch those topics. If touched, it could cause you different levels of damage. But in the West, especially now, you also see censorship everywhere— not necessarily just from the state but from companies, from institutions, from schools or museums.
Anything by or about Ai Weiwei (艾未未) is worth a read. He’s dynamic and