I do feel a bit of pressure to do justice to characters who I write that have been through terrible situations that i can barely relate to at all from my comfy middle-class sofa. But it doesn't worry me overtly, to the extent that I wouldn't write such characters.
Right there with you on the sofa!
Whether to self-censor or not is the wrong way to think about it. When you pick a sensitive subject, it's usually because consciously or otherwise, you have a desire to say something important on the issue. It is therefore your responsibility to get it right, or your message will get lost if you don't.
In addition, you can't shy away from writing the things you don't want to write about or strongly disagree with. The reader isn't stupid, and you need to make the rebuttals to the questions and counter-points that will float up in their minds (and do it subtly).
Readers aren't malleable pieces of clay in the author's hands. They will read other books, talk to other people and make up their own mind from all the sources they draw from. You've got to make your source especially sticky, so that it is always brought up in the reader's head when they are thinking about it.
Perversely, if anything, this kind of tragedy inspires me even more to right/write the injustices of this world, even if the particular injustice in the news today isn't the one I happen to be focusing on in my writing
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Separately, on video games:
There have been a number of scientific studies carried out over the years on the connection between violence in video games and whether it causes people to themselves become violent. The results you (I) may not like to hear, because it's pretty bleeding obvious when you think about it.
Yes, violent video games make people more violent. But they don't make people more likely to commit crime. I think the most recent study actually headlined as "video games make you more violent - but not by much"