be over 18 to qualify. And adults didn't seem to know what text messages were for. Then, in 1996, something changed: pay-as-you-go sim cards were introduced. Suddenly teenagers could acquire mobile phones. And when they got them, boy did they know what SMS was for. It was a tipping point. The graph turned skywards, and it's been going in that direction ever since. SMS is now the world's most intensively used data communication technology. One source claims that over 6 trillion texts were sent in 2010, for example, and that was more than triple the number sent in 2007. The story of GSM and SMS has interesting lessons for technology policy. GSM came about largely because of Europe-wide governmental action: the establishment of a continent-wide technical standard effectively created an enormous industry and gave Europe a significant lead in mobile telephony. So the right-wing mantra that governments should keep their noses out of technology policy and leave it to the market is sometimes wrong. Second, the story of SMS shows that the people who effectively invent a technology -- in the sense of determining its use and making it viable -- are not so much the engineers who design it as the consumers who discover what it's really for. The telephone was originally conceived as a broadcast medium, whereas radio was conceived as a point-to-point medium. Exactly the opposite turned out to be true in both cases. And it was teenagers who "invented" SMS. Finally, we need to stop being