It seems a bit odd that they don't say much about attribution. That's probably the main reason people are reluctant to share data -- at least for systems neuroscience, where I am. People don't want others publishing results on their data before they do, and when others do publish results they want to be cited or possibly authors.
It's also a bit unclear what makes data that different from content.
It's also a bit unclear what makes data that different from content.