To cite the FSD or DFSG freedom to modify code in support of this new excess of copyright law is an example of that confused reasoning. You cannot modify BSD-licensed code to remove the copyright header for example, and you cannot add the string “all rights reserved” to the top of a GPL-2-licensed file, yet despite restricting your freedom in this way neither license breaks the FSD or the DFSG. If the BSD license said “you may not write a script to remove this header”, would that break the DFSG?
DRM is an extension of copyright law that can prevent computer users from exercising their freedoms. Those who support DRM seem to view code, rather than human beings, as the subject of Free Software's freedoms. This is an impoverished understanding of freedom. But if you must write DRM code, the GPL-3 will not prevent you. It just removes the legal privileges that such code would otherwise have to remove users' freedom.
(Originally posted as a comment on Luis Villa’s weblog, reproduced with minor edits for clarity).