[Openstreetmap] Which CC Licence for Data-Sets?

[Petter Reinholdtsen]

[Frank Mohr]
> What do you think of "Creative Commons Attribution-ShareAlike" ?

[Schuyler Erle]
> I for one think that CC-ShareAlike makes the most sense for this
> data set.

I do not know the CC licenses very well, but I fear that a requirement
for attribution would lead to maps where the attribution list would
fill most of the map space.  I guess this would only be a problem if
all contributors would need to be attributed when making derived work.
Is this a problem with CC Attribution-ShareAlike or CC-ShareAlike?