Re: Anti-TPM clauses

[Olive <olive001@tele2allin.be>]

Ben Finney wrote:
> Freek Dijkstra <debian2007@macfreek.nl> writes:
>
> > Relevant part, in article 4a of
> > http://creativecommons.org/licenses/by-sa/3.0/legalcode
> >
> > > You may not impose any effective technological measures on the
> > > Work that restrict the ability of a recipient of the Work from You
> > > to exercise the rights granted to that recipient under the terms
> > > of the License.
> > There seem to be consensus that as long as there is no vote on it
> > (similar to 2006_001),
>
> Note that votes like 2006-001 can only change what the Debian project
> will or will not do. Voting can't retroactively make a given set of
> license terms on a work free or non-free, any more than voting can
> change the value of pi.
>
> > it's probably non-free, and best not put it in main. Correct?
>
> That's my understanding, yes. Largely on the basis that it's imposing
> a non-free restriction ("You may not ...") on the recipient.

Could you please tell more. The very purpose of copyleft is to forbid to 
 prevent someone distributing a covered work by forbidding the 
recipient to exercise his "right". This clause tell nothing more and if 
you think that it is not free, shall you say that any copyleft license 
is non free?

Even in GPLv2 there is this term (par 6):

"You may not impose any further restrictions on the recipients' exercise 
of the rights granted herein"

It seems that the restriction in the creative common is just a subset of 
this.

> > However, as a total non-lawyer type, I am confused about either the
> > similarity or difference in another well-know anti-TDM clause:
> >
> > Relevant part, in article 3 of
> > http://www.gnu.org/licenses/gpl-3.0.html
> >
> > > No covered work shall be deemed part of an effective technological
> > > measure under any applicable law fulfilling obligations under
> > > article 11 of the WIPO copyright treaty adopted on 20 December
> > > 1996, or similar laws prohibiting or restricting circumvention of
> > > such measures.
> > Could someone please decypher this legal mumbo-jumbo (I can barely
> > read the CC, but have a harder time reading this text!) and tell me
> > how this is different from the creative commons anti-TPM clause.
>
> The main difference is that there's no "you may not" or "you must".
>
> It is instead a declaration: the licensor, by choosing these license
> terms for a work, states explicitly that the work isn't an "effective
> technological measure" under copyright law. The intent is that this in
> effect prevents certain restrictive laws from applying to recipients
> of the work.

I fail to understand the difference. Let's read par 8 of GPLv3:

"You may not propagate or modify a covered work except as expressly 
provided under this License"

So together with the terms you cite the license indeed says that you may 
not distribute a covered work with DRM that would prevent to use one's 
freedom on the work.

> > What is the correct conclusion:
> > [...]
> > 3. This is clearly totally different. The difference is ....
>
> The difference is: one is a restriction, the other is not.

Some restriction are acceptable; you must tell why this is a non free 
restriction; not just that it is a restriction.

Olive