Re: PDF restrictions (was: Re: Evince update and release)

[Bryan Clark <bclark redhat com>]

On Mon, 2005-05-23 at 14:38 +0200, Christian Persch wrote:
> AFAIK, this means that the producer of the PDF can specify that the user
> --- as long as he's using an application which implements these
> restrictions --- cannot copy text or graphics from the document, and not
> print (or only print at low quality setting) the document. (I'm ignoring
> the bits about editing and annotating, since evince doesn't support that
> yet.)

Yes, this is correct.

> Could you explain the rationale for implementing this in evince? I'm
> concerned about these points:
> 
> * Legalities: 

[*] According the PDF reference the permissions are up to the PDF
consumer applications to follow.  Encryption of a PDF has provided a way
to ensure that some kind of permissions are at least followed, however
they know there is no way to prevent people from implementing an open
spec such as this and requiring them to enforce the permissions.

Here is the quote from page 98 of the PDF Reference version 1.6.

".. It is up to the implementors of PDF consumer applications to respect
the intent of the document creator by restricting user access to an
encrypted PDF file according to the permissions contained in the file."

> * By implementing restrictions, you take away the user's freedom: 

But at the same time you respect the authors wishes when we enable these
restrictions.  A users freedom and authors rights seem they are always
going to be at ends with each other.  We're allowing users to take
freedom into their own hands by having the configure option and yet
allowing people to respect authors wishes.  Really where this argument
belongs is towards authors who unnecessarily lock their documents down,
but there does exist a number of authors who do this for good reason and
should be protected.

> * Accessibility: How will this interfere with accessibility, once evince
> gains a11y support?

AFAIK the copy protection disables text/graphics extraction, even for
accessibility readers.  Page 97 of the document describes this.

Oh it's only monday :)
~ Bryan

[*] The obvious Yatta Yatta here.  This is my understanding of the
legalities and may or may not be Red Hat's official position.  I'm
speaking out of my own understanding of the law and its repercussions.
Red Hat is my current employer and will without hesitation crush me like
a bug for any and all and rumored or even not rumored misrepresentations
of it's official policies.
[1] http://partners.adobe.com/public/developer/pdf/index_reference.html