On Sat, Nov 28, 2015 at 5:23 AM, Andreas Kolbe jayen466@gmail.com wrote:
To the extent that Wikidata draws on Wikipedia, its CC0 license would appear to be a gross violation of Wikipedia's share-alike license requirement.
By the same logic, to the extent Wikipedia takes its facts from non-free external source, its free license would be a copyright violation. Luckily for us, that's not how copyright works. Statements of facts can not be copyrighted; large-scale arrangements of facts (ie. a full database) probably can, but CC does not prevent others from using them without attribution, just distributing them (again, it's like the GPL/Affero difference); there are sui generis database rights in some countries but not in the USA where both Wikipedia and most proprietary reusers/compatitors are located, so relying on neighbouring rights would not help there but cause legal uncertainty for reusers (e.g. OSM which has lots of legal trouble importing coordinates due to being EU-based).
The generation of data always has a social context. Knowing where data come
from is a good thing.
You probably won't find any Wikipedian who disagrees; verifiability is one of the fundaments of the project. But something being good and using restrictive licensing to force others to do it are very different things.