Like most 12-year-olds, my daughter got her first mobile phone a few months ago – just as she started secondary school. Year 7 is the time when life really opens up for young people: suddenly they're travelling solo to school and going out on their own, meeting up with friends to go shopping or to the park or to the cinema. It made sense to me as a parent, as it does to most parents with children of this age group, to buy her a phone.