[roc]

I don't see why you couldn't have a database of facts under CC-BY-SA. You can't copyright individual facts, but you absolutely can copyright a collection of facts as a collection. [1]

I would think the more-pressing problem would be the 'viral' nature of the 'share alike' restriction when it came to API use.

Attribution would also seem to be thorny and difficult to police, but not intractable.

[1] e.g. I can make a phone directory and copyright it. You could take all the data out of my phone directory to make your own directory and that would be fine. But you could not simply make copies of my directory and sell those as your own.

[ZeroGravitas]

But being able to legally take all the data out and making your own database (or other thing) with it (which you state is fine) is exactly what makes CC-BY-SA pointless/inapplicable to databases of open data.

See this discussion of why CC-BY-SA is unsuitable for OpenStreetMap (which mentions the case law on phone books you refer to):

http://www.osmfoundation.org/wiki/License/Why_CC_BY-SA_is_Un...

Wikipedia says this on Fiest vs Rural and collections of facts:

"In regard to collections of facts, O'Connor states that copyright can only apply to the creative aspects of collection: the creative choice of what data to include or exclude, the order and style in which the information is presented, etc., but not on the information itself. If Feist were to take the directory and rearrange them it would destroy the copyright owned in the data.

The court ruled that Rural's directory was nothing more than an alphabetic list of all subscribers to its service, which it was required to compile under law, and that no creative expression was involved. The fact that Rural spent considerable time and money collecting the data was irrelevant to copyright law, and Rural's copyright claim was dismissed."

http://en.wikipedia.org/wiki/Feist_v._Rural

[roc]

It seems to me the confusion is over what OpenStreetMap wants to control and what copyright allows them to control.

The 'shortcomings' of CC-BY-SA noted in your first link seem to boil down to use cases involving chunks of data that simply do not qualify for copyright. Thus, by definition, no copyright license could behave any differently than any other in determining what can and can't be done with those chunks of data.

A Terms of Use agreement (and enforcement) could do more, but the particular copyright license is simply moot.

[ZeroGravitas]

The ODbL isn't (just) a copyright licence, for exactly those reasons.