[OSM-legal-talk] Is CC-BY-SA is compatible with ODbL - a philosophical point

[David Groom]

Why are we changing the licence?  Well [1] states among other things that " 
[CC-BY-SA]  is therefore very difficult to interpret",  and we have indeed 
seen this situation occur many times when people have asked what can and 
can't be done with OSM data, and no definitive answer could be found.

If it was unclear if something was allowed under CC-BY-SA then users of our 
data were asked to take a cautious approach.  And that seems very reasonable 
stance to take, even though it resulted in a lower than hoped for use of OSM 
data. So it was decided that since even the OSM community could not 
categorically say how  CC-BY-SA applied to OSM data a licence change was 
needed.

Move forward a bit and we start to implement the new licence.  Since we 
could not reach consensus on how CC-By-SA applied to "our" data, it seems 
reasonable to assume that we can not assume how CC-BY-SA data applies to 
other people data, and therefor to be safe I presume we won't simply be 
blindly importing  CC-BY-SA data into OSM.  I presume we will be approaching 
providers of data that has a CC-BY-SA licence and asking if we can use that 
data in OSM.  So our permission to use the data will stem not from a 
CC-BY-SA licence, but from the explicit permission given by the copyright 
holder.

Or am I missing something?

Furthermore if we don't approach CC-BY-SA providers and ask if we can use 
their data, then we are using it by virtue of the fact it is CC-BY-SA, and 
surely the CC-BY-SA permissions "flow though into" the OSM data. In which 
case nothing has been gained from the licence change process as the same 
permissions which were there before (and were difficult to interpret) still 
exist.

Apologies if this has been discussed before, but I cant see anything about 
it on the implementation plan [2]

David


[1] 
http://www.osmfoundation.org/wiki/License/We_Are_Changing_The_License#Why_are_we_changing_the_license.3F

[2] 
http://wiki.openstreetmap.org/wiki/Open_Database_License/Implementation_Plan