At the end of the 18th century, many West European countries banned The Sorrows of Young Werther, a novel by Johann Wolfgang von Goethe. The protagonist commits suicide by shooting himself because of unrequited love. The book was banned because of a series of suicides committed by young men in the same manner. That’s when the connection between publication of information about violence and its social effects was made.
The U.S. and many European countries have legal mechanisms regulating the media when it comes to reporting on violence. Many media also have codes and standards about reporting such incidents.
In Britain it is forbidden to show close-ups of severed limbs after accidents. There are clear regulations for how many seconds and how closely you can show such videos. This is not censorship, but a way to be responsible about every word you say and every frame you screen.