More than two-thirds of US parents surveyed by Pew Research Center have concerns about what is advertised to children on YouTube. Hispanic parents -- at 74% -- rated highest in concern in the "Parenting Children in the Age of Screens" study of 4,000 parents in March. The study found many parents are also acutely concerned that their children will encounter "inappropriate content" while surfing on YouTube or in th etypes of videos that are recommended to them based on YouTube's algorithms.