A boy called Kasim found an app that promised something brilliant — "free," it said, in big friendly letters. He signed up. But to start the "free" thing, it wanted card details, "just to verify." In the small print he didn't read, the free part lasted a few days, then quietly became a monthly charge that was awkward to cancel. Kasim used a family card he'd been allowed to use for something else, not really thinking. Weeks later, a grown-up spotted a charge they didn't recognise. Kasim barely remembered signing up. "Free" had a catch — and the catch was in the part he'd skated past, because reading it was boring and the big friendly letters seemed trustworthy.