I perhaps overstated when I said it has nothing to do with it, cause it is clearly used by some companies, but with or without DRM a work is still covered by copyright law.
DRM is a method of encrypting documents which some companies use. But the Copyright law and intellectual property laws are Laws, not methods of managing. DRM is not part of the law. DCMA is a law with respect to DRM.
From Wikipedia:
The Digital Millennium Copyright Act (DMCA) is a United States copyright law that implements two 1996 treaties of the World Intellectual Property Organization (WIPO). It criminalizes production and dissemination of technology, devices, or services intended to circumvent measures (commonly known as digital rights management or DRM) that control access to copyrighted works. It also criminalizes the act of circumventing an access control, whether or not there is actual infringement of copyright itself.
In other words DMCA is another law which is in regard to DRM, but again it is not Copyright Law itself as stated in that second phrase of the last sentence.
Copyright law is the law that protects the authors of works against unauthorized copying of their works. (and has nothing to do with how they might go about protecting it -- DRM or otherwise).
BTW: there was no intent to say that post was off topic, certainly it is related, but copyright has been around much longer than DRM or DCMA.
