There's a difference between watching fatal car accidents or faked scenes in movies as opposed to live criminal acts of violence on real people, but there are certainly grey areas too. Who hasn't seen people jumping from the World Trade Center fires?
We're drawn to, and learn from, the plight of others, but there are also legal standards to protect real people who are being filmed while being criminally abused, rather than just acting the part in a video portrayal of such.