Types of Censorship

Moral censorship
Due to obscenity or moral questionability
Pornography, books and films
Military censorship
Confidentiality of information to protect from military enemy
To counter espionage
Political censorship
Government holds information from citizens
To prevent rebellion
Religious censorship
Material objectionable to a certain faith
Corporate censorship
Media outlets publish no information that portrays business partners poorly

Gray situations and questions to consider:
Political censorship in wartime?
Is refusal to teach Creationism in schools censorship?
Violation of freedom of speech?
Censorship and restrictions on videogames: should some games be outlawed or restricted due to obscene material?
“Now if we can identify certain evils, and if advocacy of those evils seems likely to encourage people to commit them, then why should we not take the next and logical step and prohibit such advocacy… Must the authorities be helpless to restrain the source of the evil?” – Thomas Stork

Censorship in China
Worst-rated internationally, press “not free”
Largely to maintain rule of communist party
“censorship prevents Chinese citizens from discovering or learning more about past and current failures of the Communist Party that could create or inflame anti-government sentiment. Measures such as the blocking of foreign governments' websites may also be intended to prevent citizens from learning about alternative systems of governance and demanding similar systems.”
“Foreign news broadcasts in China such as CNN, BBC World Service, and Bloomberg Television are occasionally censored by being "blacked out" during controversial segments.”
“Blacked out content has included references to the Tiananmen Square protests of 1989, the Dalai Lama, the death of Zhao Ziyang, the 2008”
“Tibetan unrest, and negative developments about the Beijing Olympics.
at least 18,000 websites are blocked from within the country. Banned sites have included Wikipedia, Google, YouTube, Flickr, and the BBC.”
Text message surveillance centers used
“Educational institutions within China have been accused of whitewashing PRC history by downplaying or avoiding mention of controversial historical events such as the Great Leap Forward, Cultural Revolution, and the Tiananmen Square protests of 1989.”
“International corporations such as Google, Microsoft, MySpace, and Yahoo! willingly censor their content for Chinese markets in order to be allowed to do business in the country.”