Here's a clip I came across---Justin Bieber on CSI:
Stuff like this--seeing a teenager horribly killed--is deeply disturbing to adults, but you have to look at if from the young actors' point of view.
When Ron Howard was Justin Bieber's age, he was blubbing like a little girl on a three-part episode of Lassie. British teen idol Jack Wild was a year older that Bieber when he starred on H.R. Puffenstuff. You don't think they desperately wanted to play violent criminals? You don't think teenagers found roles like these demeaning?
Henry Thomas, the little boy in E.T., went into acting because he secretly hoped to appear in a Star Wars movie. Corey Haim was interviewed after the movie Lucas and said he wanted to play Rambo's long lost son who becomes his sidekick.
Christopher Knight, TV's Peter Brady, wanted his character to run away from home and become a juvenile delinquent.
But you do have to consider the adults in the audience.
Alfred Hitchcock made the mistake of blowing up a child in the movie Sabotage. It completely alienated the audience. Hitchcock never did that again.
There was a movie called Children at Play. It was a dirt cheap Troma Team production. It was about children who turn feral and start coming out of the woods and killing people.
When they were filming, they started out trying to shield the child actors from the violent gore effects, but the kids loved it. They loved seeing that stuff. And the people making the movie had made so many bloody, violent horror movies that they were desensitized to it and lost touch with how audiences would react. They found this out at the Cannes film festival.
At Cannes, they didn't show Children at Play----they just showed a preview for it. And the audience that came there expecting to see a bloody disgusting horror movie, were so offended at the trailer that they all walked out.
I guess I'm not giving it away here since it was in the trailer, but the movie ended with the parents capturing and massacring the feral children, killing them in different ways, with different farming implements and so forth.
I don't know how the child actors felt about this. I didn't notice any trying not to smile as they were brutally killed. If they had, it probably would have taken the edge off.