Not only China & Saudia but countries like Sudan and Hongkong also has already banned vulgar and violent videos & audios plus all porn websites.
Justification behind this is they want to save their youth from such evils which affect future of country. Recently in India also we saw , it was proven - like in the case of Shakti Mill , Gudiya, and in many other cases, the accused were watching porn. In many cases the rapes were committed with very reason of making a porn clip.
So We want a BAN on Porn websites, Pornography , textual audible and sexual activities along with on screen violence.