[cc-licenses] [Foundation-l] [Commons-l] Requirements for a strong copyleft license

James Grimmelmann james at grimmelmann.net
Mon Dec 3 17:34:06 EST 2007


On Dec 3, 2007, at 3:32 PM, Terry Hancock wrote:

> This may or may not be included in the concept of copyleft as used by
> the GPL, but I think the argument that the definition of  
> "derivative" or
> "copy" under copyright law constrains the extent of copyleft is false.
>
> Copyleft is presented not as an alternative to copyright, but rather  
> as
> an alternative to *financial compensation*. Instead of charging a fee
> for the license to use the copyrighted material, we insist on  
> conditions
> of use. Thus the limits are on what kind of fee can be charged for a
> copyrighted work, not what works can be copyrighted.
>
> So long as the use is not something which is otherwise allowed under
> "fair use" or "fair dealing" provisions of copyright law, then, you  
> need
> a license to use the work. In principle, just about any
> legally-admissible contract requirement can demanded as a condition of
> that use (you are always free not to use the work -- too harsh a set  
> of
> requirements is like charging too much money for a work).

This is right, and it provides a chance for a quick interjection on  
terminology I've been meaning to make for a few days.

I would say that "weak" and "strong" copyleft are misleading terms  
because there's a continuum of strength.  A completely non-copyleft  
license is at the weakest end.  The strongest end (call it CC-SA-to- 
infinity) would be something like a requirement that the licensee  
agree to license everything she copyrightable she creates under the CC- 
SA-to-infinity license.  If she doesn't so agree, she can't use the  
original CC-SA-to-infinity licensed work at all.

This conversation started out of a belief that the current version of  
CC-BY-SA, as generally interpreted, is too weak, and that a strong-er  
copyleft version of it is needed for Wikipedia integration.  That's  
led to an interesting and important discussion about what that strong- 
er copyleft license would look like.  We should be careful about  
calling that strong-er version "the" strong copyleft version CC-BY-SA,  
because there are a lot of different degrees of strength it could  
take.  I'm not sure there'll only ever be one possible "strong"  
version of CC-BY-SA worth talking about, and I wouldn't like to end up  
in a situation where we need to talk about the "strong strong  
copyleft" or the "double-strong copyleft" or "beyond strong copyleft"  
or "PowerThirst copyleft" or the "less strong copyleft."  Especially  
if something like Erik's final goal -- you can embed a CC-BY-SA+ item  
in some kinds of larger works that are under free but non-copyleft  
licenses -- is part of it, "strong" by itself is going to be a bit of  
a misleading description.


> Of course, courts have in the past invalidated contracts on the basis
> that they make "unreasonable" or "unexpected" demands that were not
> understood by the party agreeing to the contract, and so invalidated
> contracts. So, there's probably *some* limit on copyleft. But I'm
> reasonably certain that "what could be considered a derivative under
> copyright law" is not it.

This is also true; there's a limit on how strong a strong copyleft  
will be enforceable.  I'd guess that sometime before that point, the  
stronger copyleft actually becomes counterproductive because it deters  
too many people from using it at all.

James



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