OpenStreetMap
For the longest time it was claimed ODBL would better protect data than CC-by-SA in some jurisdictions, with the US being one of those.
However the opposite seems true, since the above claim was based on the premise that creating maps wasn't a creative enterprise.
The ODBL doesn't place a limit on what license produced works can be licensed as, they can be published as PD/CC0.
In any case unless the copyright license contains no derivative clauses people are then able to derive data from produced works and that derived data can be used to build a vectorised database.
There is one clause here where countries with database rights, when the data re-enters those countries the database right might re-apply, but this doesn't apply for countries like the US (or Australia for that matter).
Although I'm told that the above section of Database Directive in EU is untested in court, and I think some CC licenses already waive database rights and going into the future I believe creative commons plan to include this in more licenses.
One more point for those that might claim this would be difficult to do large scale, SVG files like the ones osm.org publishes are produced works, even though they aren't raster images, so converting to SVG and then back to map data would potentially be pretty trivial.
In other words CC-by-SA protects data better than ODBL, which is the complete opposite that we keep getting told.
The reason CC-by-SA will protect map data is copyright laws cover maps and the creative effort that goes into making them, it doesn't care how the map is stored, so while database protections are usually tricky this isn't the case when it comes to maps.
