Hugh McGuire is the Founder of LibriVox.org, a volunteer service that created audio books from public domain books. In his Open Letter to Ministers Prentice and Verner he discusses some of the harmful implications of legal protection for digital locks put around public domain or otherwise liberally licensed works.
An all too common misconception about legal protection for technical measures is that it is like legally protecting locks on our houses. The problem is that these locks are often applied by other than the owner of the content or the devices being locked down, something that should be legally prohibited -- not protected.
the bigger problem as i see
the bigger problem as i see it is that it makes breaking locks - and the tools to do it - illegal. there are all sorts of reasons why you might want to legally break a lock. the thing that ought to be illegal is stealing.
http://hughmcguire.net