Why is violence accepted and isn't?

Nowadays films and telefilms depicting violence have been being shown on TV all the time. I am talking about all those footages in which you can see fightings, killings and other atrocities like that. But they are accepted and most people don't care about it. On the other hand if hypothetically we televised footages (as in the case of o movies) protests would arise so fiercely that prime minister should resign :) (this might really occur here in Italy - I am from Italy). I know o movies are known to depict in a mechanical and b way but anyway they are related with something positive like our bodies and pleasure we can draw from. Instead films showing violence are undoubtely about something higly negative like death and destruction of human body. So I ask: Why is violence accepted and isn't?