As such any acts which may encourage commerce must be subordinate to expression. Restriction of expression is grounds for overturning acts which encourage commerce. Yet it is important to emphasize that this is a very narrow holding. The owner of a DVD must clearly circumvent access controls, otherwise they do not own it. As for practical means, consider Napster.
Audio files are several orders of magnitude smaller than motion pictues.
The scope of any motion picture infringment is accordingly much smaller and easier to notice in a network or server. Hence there are alternatives that are less restrictive-let copyright law work. This is specious. The same can be said of formulas for gunpowder or discussing bomb making activity for criminal purposes over the Internet. In advance of even the possibility of a crime it calls for the suppression of speech.