yeah I see what you mean, the problem with this is that the child usually has parents
I was a kid I said things but my parents punished me when I was bad and reward me when I was good, tv and stories aren't a substitute for parents and they shouldn't be in the first place. My mom always saw what I saw just to make sure the thing I was seeing was good, also she liked them too XD, and check my reactions to see what I got from it, then she would answer my questions and then left me alone when I wanted to see one of my movies, since she knew I understood them in a good way and they where safe for kids
if the kid is saying kill kill kill then tell that kid to stop it or he will be punished, it's that simple give your kids and education and he will grow up right, leave him to his own devices and he will turn out bad
why do people always blame the entertainment and not the parents I wonder?