The "Open Data" is the ability for any citizen to have access to the data collected by the local authorities as part of their work. No personal data on the citizens themselves but the statistical data which helps understand how local communities work.
This "freedom of the public data" mouvement is mandatory for all administrations according to french law.
As mentionned by the Gaztte : the state administrations and local authorities need to learn how to incourage the use of public data.
Let's give back to Ceasar, many cities have shared with us their water fountains and a huge part of the waterpoints found on FreeTaps comes from the non-profit organisation Open Street Maps.