While I agree that the "shock factor" is what some people, not just teens, need to take some situations seriously, there are some people (of all ages) whom simply are overly disturbed by images such as this. While I do think it was ok to share this material with high school kids, it would have been respectful of the instructor to mention how graphic some of the pictures are and invite people to turn their heads if they need to. My niece, whom we helped raise has had a lot of trauma and loss in her life and images such as these, really put her in distress. If she was shown these in a class at school, she would have had to be picked up from school. I had a cousin that was a under cover drug agent. He agreed to do a program for our teen church group. I was shocked at the pictures and stories he shared with these kids but it made a HUGE impact on them. They are all college or older now and they still remember that program and not one of them has touch drugs.