The aim of this research is to ask what ‘free’ and ‘public’ mean in the context of wireless networks. Is it free as in beer? Or free as in speech? Should it be ‘free at the point of access’? Or is it free because we are the product? This practised-based research aims to investigate people’s understanding of free wifi and also looks critically at the design aspects of wifi interface through the design of a cultural probe in the form of a ‘captive portal’. Presenting the project as a work in progress, this paper outlines the insights gained through the design process and also points towards the potential contribution of participatory design methods such as cultural probes to critical design practices.