The Netflix drama '13 Reasons Why' is so controversial, parents across the nation are being put on alert. The show deals with a high school student's suicide and singer Selena Gomez is one of the executive producers. The series has a TV-MA rating, meaning it's for mature audiences. While it's not suitable for kids under 18, it's very popular among teenagers. That has school principals concerned that parents are clueless to the fact that kids are watching the show on their mobile devices.