Jonathan Corbet wrote a piece on LWN about Okular and it's implementation of user permission restrictions in PDFs (sometimes errantly refered to as "DRM"). This is actually something it has done since it was KPDF back in KDE 3. Obviously, permissions in PDFs are a generally misguided attempt at protecting the agenda of a publisher in a demonstrably ineffective way that comes at a cost to things like the concepts of fair use.
So what's up with Okular having support for permissions? It's quite simple: not only is permissions in the PDF spec, but there are organizations in the world who, for contractual or legal reasons, require permissions in PDFs be respected.
Do we simply not serve those users needs? Do we "know better" for the user who says "I want to accept the terms of the publisher of this document"? Of course not; that's rather user unfriendly in itself.
So the strategy adopted was quite simple: make it an option that the user may choose to abide by the permissions flags in a PDF or not.
With the KDE configuration lock-down system, this can even be made as a policy decision within an organization, either by providing a locked-down default value for this option or just removing the option altogether with the "skip_drm" KAuthorization entry. It's even a compile time option for those who wish to be particularly hardcore about it: -DOKULAR_FORCE_DRM.
The important point, however, is that Okular (and KPDF before it) does not make that decision for the user. Okular is intentionally crafted in such a way that permissions are not pushed on anyone while at the same time not removing it by force from anyone either.
That choice is the ultimate in user respect.
As for KDE itself, as much as such a statement can be made for a globally distributed community of individuals, we do not support the notion of permissions in principle due to its impact on individual rights and freedoms. If we felt otherwise, we'd simply enforce permissions in PDFs rather than go to lengths to make it optional.
There's an old addage that goes something like "I may not agree with what you say, but I will defend your right to say it". With Okular, we do not agree with permissions but we do defend your right to opt into it should you wish. We do not see it as our role to go around telling others what they can and can not do and "fixing" PDFs by ignoring permissions with no option to do otherwise. By the same token, we also do not see it as our role to remove rights from the user and force such silliness on them either: if you wish to disagree with the author's usage of permission restrictions, you are empowered to do so with Okular.
You choose, and we defend your right to do so.
(Albert Astals Cid has also blogged about this issue. It's a nice read from one of the primary people behind KPDF/Okular.)