Teenagers love their phones. All day. Every day. Even at night. And while there are lots of really great things about smartphones, there are so many pitfalls — strangers, bullying, porn, sexting. How do you guide your teenager's digital life? Find out when Maggie Dent talks with Dr Ginni Mansberg, GP and co-author of The New Teen Age, a book which looks at what teenagers are up against on their devices.