There was some discussion of this (potentially restricted speech) at
 BTW, I've now searched for all four terms, and
Also, Dr. David Touretzky at carnegie-mellon is knowledgeable about
both DeCSS and Adobe encryption and various other first amendment
issues ignored by the DMCA (and, it seems, the Church of Scientology);
his arguments seem generally lucid and measured; you can visit his
page at http://www.cs.cmu.edu/~dst/
if you care to.