[jpollock]

From what I remember, the US doesn't allow "sweat of the brow" arguments to protect databases.

http://en.wikipedia.org/wiki/Sweat_of_the_brow#US_copyright_...

So, while the data would be protected in other places, such as the UK, it wouldn't necessarily be protected in the US.

[Doctor_Fegg]

That's why ODbL has a contract layer as well as a copyright layer - so that it applies in the US as well as the UK.