What is a computer? A stupid machine that only knows two states (power on/power off) and works according to rigid rules. A mass product, operating on ready-made software wich makes life at work or home easier, more exciting or more fun, or at least could do so, as handling it can at times be a nerveracking experience, when problems crop up, the cause of which cannot be fathomed no matter how often you read the manual and/or ask expert advice. Everyone who has ever worked with local or interlinked computers is familiar with this phenomenon. But there is also another type of working with computers, the "pure love of machines" of programming virtuosos, so-called hackers, as the psychologist and sociologist Sherry Turkle described them in her book "The Second Self" (1984), published over 10 years ago and now considered a classic. The media is fond of reporting as spectacularly as possible about pale, spotty youths, getting into other people's systems, pirating software or programming viruses that make the unprotected exchange of data dreadfully dangerous, fuelled by pizza and litres of coffee. People shake their heads in incomprehension. How can sensible people - unless it were financially lucrative - waste their time with such activities?