Children who are active on the internet are performing significant design and programming activity without realising it, in the course of hacking little animations, game scripts and so on. What does such effortless learning suggest about how to support end-user programming? This paper presents observations of 'unwitting' design and programming activity by a small group of teenagers, aged 12-17. It analyses their adoption and appropriation of technology, and discusses how such practices are embedded in social networks.