kreynolds said:I don't see how this is any different. If each and every PDF you sold included a EULA, that would be one thing, but no license agreement is included with these PDFs. Now, it could be said that the DRM itself is a form of license agreement, in which case the license, as far as I can tell, does indeed step on my rights to give the PDF away to someone. Such a license is fully within your right to use, and I'm not saying otherwise
So let's be clear, DRM doesn't change the fact that I have the right to give away something I purchase. A EULA (i.e. DRM, in this case), however, can to my understanding, lawfully and legitimately override that right. I fully understand this. If I purchase a game, but I don't like the EULA that says I can't make a backup copy, then I can never make use of the game. "Breaking the seal", as it were, means that I agree with this EULA. So, in the case of DRM, interpreted as your EULA, I won't purchase your PDFs. Why? I don't agree with your EULA.
End-user license agreements are themselves invalid and unenforceable because they unilaterally introduce stipulations after the sale, which is forbidden under contract law. The Supreme Court has said as much, but this does not stop software companies from cowing most consumers into compliance with threats of litigation. For a contract or license to be enforceable, it must be negotiated and agreed upon before any transaction takes place. This is what most people seem to be missing: for DRM to even be legal, its full impact must be disclosed to the consumer before the sale. Otherwise, it is invalid, and (if it reduces the utility of the product while purporting to enhance it) possibly also fraudulent.