CC0 has been getting lots of love in the last couple months in the realm of data, specifically GLAM data (GLAM as in Galleries, Libraries, Archives, Museums). The national libraries of Spain and Germany have released their bibliographic data using the CC0 public domain dedication tool. For those of you who don’t know what that means, it means that the libraries have waived all copyrights to the extent possible in their jurisdictions, placing the data effectively into the public domain. What’s more, the data is available as linked open data, which means that the data sets are available as RDF (Resource Description Framework) on the web, enabling the data to be linked with other data from different sources.
The National Library of Spain teamed up with the Ontology Engineering Group (OEG) to create the data portal: datos.bne.es. The datasets can be accessed directly at http://www.bne.es/es/Catalogos/DatosEnlazados/DescargaFicheros.
The National Library of Germany, aka Deutsche Nationalbibliothek (DNB), has documentation on its linked open data under CC0 here. CC Germany reported the move, and a post in English can be found over at Open GLAM.
Relatedly, the Smithsonian Cooper-Hewitt Museum, a major design museum in New York, has released the collection data for 60% of its documented collection into the public domain, also using CC0. The data set is available on a repository in Github; you can read more about the move at http://www.cooperhewitt.org/collections/data.
To learn more about Creative Commons and data, including a recently updated FAQ, check out http://wiki.creativecommons.org/Data.