What is the purpose of censorship? (hays code,watershed,music videos)

What is the purpose of censorship?

Censorship is to provide guidelines in media texts and to block out explicit content from the viewer.
This is so the viewer doesnt get offended by any content that could be seen as derogatory in anyway or holds any explicit content, becasue of this The Hays Code was introduced.

The Hays Code was introduced in the 1930's as a Motion Picture Production Code it was named this as Hollywood's chief censor of the time was Will H. Hays,these codes were a set of rules that censorship guidelines followed.
So this meant the Hays Code decided what we viewed they made sure what was to be shown was to be censored as things that was seen as too explicit would curropt are youth and change peoples ideas and views.  The type of things that wasnt excepted and they would censor out would be: Sex relationships between the white and black     races, The use of the flag in a bad way, Arson, Firearms, Theft, Brutality, gruesomeness, murder, smuggling, Prostitution. The Hays Code was enforced in 1934 but later abandoned in 1968 due to The MPPA film rating system,this is what we follow today ed movies rated from U/PG-18 and R Rated.

A Watershed is when programs with adult aspects may be broadcast at a certain time.
It divides the day into the overnight sections where family oriented programming for a younger audience may be aired and where programming aimed at adult audience is shown, though not required.
Examples of adult content include, but are not limited to, graphic violence, strong language, nudity, secual scenes and drug use.
 In most countries, the same set of rules also applies to radio commercials and tv commercials, both for the content of the commercial and the nature of the product or service being advertised.

Today there is quite a heavy censorship on music videos especialy on MTV.MTV had concored number of music videos to remove references in lyrics to drugs,sex, nudity, violence, racism, homophobia, and completely removing or editing out the swearwords.MTV will also censor any content that is a concern to copyright holders. here are some examples:
"express your self" by N.W.A censored the words "i have a dream" when the group goes through the banner with the statement  while Dr.Dre began rhyming.
When the music video for "paper planes" by M.I.A. was released on MTV, the word "weed" was removed from the second verse, and the gunshot sounds that are heard in the chorus were replaced with cash register sounds in order to remove references to murder. Also, the singer's vocals were edited to take away from the song's mature content. This angered M.I.A. greatly, and she publicly spoke out against the censorship of the song on her Myspace blog.
The issue with this is that this doesnt approve to every music station and some show the un censored versons which is free for younger ages to watch,also things like youtube being able to upload any music video and having accounts such as vevo have made it harder to censor for all contries as it depends on where you are in the world.