Many books see characters suffering through trauma, violent battles, or something negative. As writers and students we are often taught to build to a 'climax', and never make it too easy for our characters, that it is good to make readers worry about characters, which forms a bond between them. But I bring this question to you: how far is too far?

I've read books where this 'tormenting' reaches extremely varied levels. The general guideline seems to be that in books for younger readers the level of 'torment' is much lower, e.g. the hero gets stopped and almost killed by a super villain (sometimes, only captured/temporarily stopped from completing their mission). This contrasts from the extremities of adult fiction, the worst I've seen is where a character's body parts begin to get cut off as they are tortured by antagonists.

What, you're spoiling my fun! No, I'm not saying at all that anything stated above is 'not acceptable'. I'm simply wondering, is there a point where it goes 'too far' and we begin to question the morales of writing such a story? Violence is such a major part of our world as well as the book universe, I really don't think it should be removed from book world, but would not writing about violence decrease levels of violence in our world?