The original and essential value of spatial data - data that refer to specific geographical locations or areas - lies in environmental and other decision making, and thus, such data mostly originate in the public sector and are subsequently made available to people, companies, and public bodies. In the European Union, a complex system is in place by which the provision of spatial data is determined according to a tripartite distinction: sharing among public bodies for environmental and other policy purposes, public information or access upon request, and re-use for commercial or non-commercial purposes based upon the economic value of the data. How well does this distinction hold up against actual demands? It is the contention of this book that these three categories overlap in practice, and that the rules that emerge from this distinction - and that govern use of the data - are rendered ineffective by the character of the public task, which remains contingent, evolving, and political.