It's a difficult topic for some people. It's free speech; being offended is not a reason to disallow it. However, harm may be. That said, there are some people who are "triggered" by images that others are not. Some women who have lost a child may be triggered by images of children. Some people can't look at pictures of spiders. What about those anti-abortionists who use graphic images of aborted fetuses (which some claim are fake) in pieces? Many people complain about that last one. Some images are hidden, for the most part. Sexually explicit images, while sometimes sent to cellphones and computers without the users' permission, are, in general, not posted on billboards and in the general public. Still, graphic violence is much more available.