The biggest risk is not so much the danger of being harmed but the danger of missed opportunities, especially at school. As we point out in, Online Safety 3.0: Protecting and Empowering Youth, schools too often block access to social media and fail to use it in the educational process. While it's true that there are some online activities that ought not to be done during school hours, banning all social media is the 21st century equivalent of banning all books just because some books are inappropriate for use in school.