I do NOT make a case against copyright. On the contrary, I support copyright "An Act for the Encouragement of Learning, by Vesting the Copies of Printed Books in the Author's or Purchasers of Such Copies"
The original statue gives rights to both the author AND the purchaser. This has recently been re-affirmed twice by the Canadian Supreme Court. 

The original Act clearly states that authors "shall have the sole right and liberty of printing such book and books for the term of one and twenty years . . ."
See:  http://presspubs.uchicago.edu/founders/documents/a1_8_8s2.html

A monopoly (from Greek monos μόνος (alone or single) + polein πωλεῖν (to sell)) exists when a specific person or enterprise is the only supplier of a particular commodity.

So, even today one's "copy" right gives one the monopoly over their works. This is a privilege given to authors -- the rationale is that this will encourage learning. I am not arguing whether the monopoly is "good" or "bad", just that it is what it is. And I support this monopoly for authors. I do not support the extension of this right almost in perpetuity, even when authors don't ask for it.

I would support the extensions, if after 20 years or so, authors who want to continue their copyright would have to pay a nominal sum to do so. In that way only works of some commercial value (or perceived commercial value) would have extended copyright.  Today there are millions of creative works that are "orphans". They have little or no commercial value and the authors are dead and their heirs are unlocatable. They exist in a copyright 'limbo'.

Publisher are continually trying (unsuccessfully so far) to change copyright. They would like to morph their privileged monopoly "copy" right into a "property" right. 
However, the courts in both Canada and the USA have both ruled that copyright is NOT a property right. For example see:
R. v. Stewart 1 S.C.R. 963 para 40, Supreme Court of Canada (1988). Retrieved from
http://fullcomment.nationalpost.com/2011/10/26/jesse-kline-on-copyright-reform-and-the-case-of-the-illicit-t-shirts/
And
Rosenoer, J. (1995). Dowling and stolen property Retrieved from http://www.cyberlaw.com/cylw0195.html

Aaron Swartz (quoting Prof. Bernstein) explains the "freedom" argument better than me: See
http://www.aaronsw.com/weblog/000829