Not a parent myself, but my 13 year old sister has been on the same policy now that my parents are older and sick of being the bad guy like they were with her older siblings. Not a stretch to say she is addicted to youtube. Watches for 12+ hours a day on the weekend, rushes home after school to watch as much as possible before going to sleep at midnight earliest. Her grades are solid, but she has 0 social life or interests really besides youtube. Clearly everyone is different, but it does seem wild to me how some kids are able to control themselves with the internet and some seem unable to.