The often heard statement 'I don't have anything to hide' catches the naivety of contemporary internet users with regard to their privacy. Facebook appears as an innocent medium, in which we can manifest our persona in the public space. As such, we appear to make use of a medium as if writing a public diary. But at the same time our behavior patterns, buying preferences and political views are being mapped continuously etc. These data can be used for commercial purposes as well as political purposes. Landeweerd will show in his lecture that, in this sense, we are the product, not the customer.