[OSM-legal-talk] Are CT contributors are in breach of the CC-BY-SA license?

[Francis Davey]

>
>> That is the situation you are describing.
>
> I'm not sure what you mean by "the situation you are describing", but

Ah, this is where we are probably at cross purposes. I am sorry for
that - its been a long thread. 80n's original query concerned
uploading work to OSMF by someone who has agreed to the contributor
terms. That is a sublicence (because it is expressed that way) and
that is something which CC-BY-SA does not permit (I think we agree on
that point).

> it's not how CC-BY-SA works, since CC-BY-SA specifically says that it
> does not grant permission to sublicense.  Instead "Each time You
> Distribute or Publicly Perform an Adaptation, Licensor offers to the
> recipient a license to the original Work on the same terms and
> conditions as the license granted to You under this License."
>

... and my mistake, yes of course the right to sublicense applies only
to derivative works. Under the US 3.0 at least, the CC licence grants
a right to sublicence derivative works but not the original work.

> Under CC-BY-SA, X licenses the work to Y, Z, and any other third
> party, granting permission to distribute the work under [the terms of]
> L1, L2, or any other Compatible License.  The licenses to the
> contributions of X come from X, not from Y.
>

Yes.

> If Y made modifications to the work, Y's license covers only Y's
> modifications.  If Z then makes modifications, Z's license covers only

No. Y's licence covers the whole of the derived work. X's licence
covers all the work as not modified by Y. Z benefits from both those
licences as against the respective licensors, which makes sense.

> Z's modifications. I assume the reason this is done is to simplify the
> chain of title, and also to avoid complications with copyright
> transfers, inheritance, infringements, etc.  On the "why" though maybe
> a CC list would be the best place to ask.
>

Yes, that was my  understanding. The CC model is a new licence to all
users of the work from the original licensor which avoids problems
with chain of title. To the extent that CC licences are not contracts
this is fine. Certainly in the UK CC doesn't rely on contract to work.
I suspect there are more difficulties with ODbL style contract-reliant
effects to third parties of this kind.

Anyway, as you say this is fairly off topic and not what 80n asked.

-- 
Francis Davey