I asked for a link because you can say anything you want, but just saying it doesn't make it true. You have to provide evidence of why you're right.
But the article you provide doesn't provide the evidence you thought it would. From your Wikipedia article (emphasis mine):
Censorship ( Latin censura) is a restrictive procedure of usually government agencies in order to mass media to control or in the personal transport mediated.
Usually does not mean always, which is what you're trying to say.
So the Catholic Church established its ban heretical writings
The Catholic Church is a religious organization, not a government.
Just take a look at the Motion Picture Association of America. When it was first started, it was led by Will H Hays, and he was not in the government at that time. He was censoring based on the perceived offensiveness of content.
Either one. Censor is both a noun and a verb.
The pressure to censor media comes from many different places. Government is one. Religious organizations are definitely another, as well as independent organizations (such as the MPAA).
If you're editing to remove "offensive" content, then you are censoring (you can be both an editor and a censor, they're not exclusive). If you're editing to correct grammar, spelling, sentence flow, etc., then you're just editing. Schizophrenia has nothing to do with it.
Here's an example of censorship not done by a government body. You ever play The Legend of Zelda: Ocarina of Time? In the Fire Temple, Nintendo had originally put in some background chanting. However, the chanting was apparently sampled from an Islamic prayer. In the fear that it would offend Islamic people, Nintendo removed the chanting (see http://zelda.wikia.com/wiki/Controversy.
Or how about Dragon Ball? In Japan, where casual nudity and sex isn't quite the big deal it is in the US, several images and scenes from censored. A list of examples are found at http://dragonball.wikia.com/wiki/List_of_Censorship_in_the_Dragon_Ball_series.