executive summary for those who find my rants long (because they are)
pull the DRM code out of KPDF as it will primarily aide and abet ethically questionable practice, is technically flawed because it's open source and reinforces the usurpation of legal process by private interests.
is DRM in eBooks ethical?
it is often within the rights of and ethical for authors and publishers to restrict freedoms. even the GPL, poster child of the Free Software licenses, relies on restrictions enacted through copyrights and license to guarantee certain things can not be done. so simply saying DRM restricts freedoms does not mean it's unethical or somehow inately wrong.
but restricting certain types of freedoms is. for instance, it is generally considered unethical to restrict some one else's freedom of speach outside of certain exceptional circumstances. similarly, removing someone's rights to fair use and negating the doctrine of second sale is also generally considered not right. because of this, second hand book and music stores are possible and even thrive. you know, like Amazon.com ;) these issues have been tried in the courts of the USA and other countries and things like photocopying, second sale, etc have been upheld. so now industry is trying to work around the legal system by inventing one of its own where the judge and jury are themselves and the police are bits of DRM code.
since this is the most common use of DRM when it comes to media, DRM is usually considered to be generally negative. and this is before we even get to looking at secondary effects like making eBooks non-accessible to those with disabilities as it removes their ability to recode the data into a something they can use.
so while DRM itself is not unethical in my opinion, it's general application today in eBooks more often than not is. invent all the possible good uses for it you want, in the real world it's used to limit previously guaranteed rights and to rob the blind, well, blind.
but there's something that trumps all the philosophizing in the world: pragmatism.
DRM + source code = no DRM
let's get realistic: DRM only works when the user has their freedom removed prior to the DRM being introduced. it's a lot like sucker punching someone when they are expecting it: it's much easier to accomplish this task when you have a couple of friends holding them down. otherwise they can just step out of your way.
DRM is a freedom removing sucker punch. i say it's a "sucker punch" because it isn't tied to any mutual interests between the creator and the audience, nor is it done with any consensus outside of the will of the publisher (which may not be the creator). no, instead DRM tries to enforce the will of the publisher by forcefully removing freedoms by implicitly assuming the user can't simply remove the DRM enforcement mechanisms.
obviously you can't count on this if the user has access to the source code.
so what's the first thing that will happen when KPDF gets released with this DRM code? someone, or more likely many someones, will simply fork KPDF, remove the DRM mechanisms, and distribute that. seeing as there is no effectivity to the DRM mechanisms in KPDF, all it does is encourage forking of the software. is that a worthwhile result?
what does eBook DRM really protect?
the thornier issue that i'm not going to really get into here is the question of what eBook DRM is really trying to protect. others have done a much better job of covering this question with proper, book-length answers than i ever could. so i'll keep it brief.
DRM protects a business model that relies on something that no longer is true: that it's prohibitively expensive to copy large volumes of information. instead of looking at ways to reform the premise of the industry and instead of engaging the consumer market, they are trying to force the world back into the 1800s by making modern technology behave more like antiquated technology. how could the business of publishing be changed to keep up with technology, rather than try and deny it?
DRM also primarily protects the publisher. not the author and not the consumer. if the author and the publisher were more closely related that would be one thing. today, they often aren't. this tends to raise people hackles. publishers need to reexamine their place in the world, or risk taking down not only themselves but also the authors many of them truly wish to promote and help through their creative process. most disgusting is the use of DRM by publishers on works that are in the public domain.
DRM also protects business interests from the law. by creating their own extralegal means to define the rights of the audience, we are seeing the formation of a dangerous precedent: economic interests playing the role of government.
these are just some of the Big Questions with Hard Answers. just ask Lawrence Lessig.