Censorship

In order to allow songs to be played at any time censorship takes place, they make many restrictions which can include :

Blanking- The volume is muted for the entire uncensored word for example blanking out swear words in songs

Beeping- Playing a beep or sounds over all of the word or part of the word

Repeating-Repeating the word used before the explicit word is used, canceling out the explicit word

Skipping-Deleting the word from the song without time delay 

Echo-Instead of saying the word, a word from the previous line is echoed. 

And Many More ..

However due to Censorship many video's have been banned or have only been played after the watershed of 9pm, some examples of these are : 

Cher ' If I Could Turn Back Time' was banned from being played on the music channel MTV due to her very minimal about of clothing worn in the video, which MTV found too revealing in 1989, to this day the video is only played post-midnight on MTV and the 'Clothing' worn still remains iconic. Offical Video For If I Could Turn Back Time

Madonna ' Justify My Love' was also banned in 1990 by MTV because it was seen as just too explicit, with scenes including Bisexuality, Sadomasochism and Erotic Sexual References, unfortunately the video is just too erotic for me to display a link, so here is a Newspaper Article On The Banned Video You can also see the official Madonna Website for more information here and too see more videos of Madonna's her official Youtube site is Here.

Marylyn Mansons video for his song 'Saint' also caused some controversy with the censorship. When his video became scrutinized, and Marylyn had to take the blame for somehow being responsible for the Columbine School Shootings, from the content of the heavy metal video.
The video can be found on Youtube still, but has an age restriction of 18, however this does not necessarily stop teens from gaining access to the video, as anybody could lie about their age in order to watch the video. This highlights how un-effective the media online is today with age restrictions and many more things.

A more recent video to cause controversy was Rhianna's video for S&M, which has been banned in 11 countries so far and cut from Radio 1's playlist. The video features Rhianna sucking on a banana and simulating sex with a blow up doll. MTV have re-edited the music video in order to produce a suitable version for the day time TV. The un-edited version can be found on Youtube and Post Watershed on MTV, however on Youtube they have placed an age restriction of 18 or over in order to watch the video.
The article of all this information can be found from this link S&M Banned Article.