[ Update on 2014-05-13: If you're more of a listening rather than reading type, you might enjoy the Free as in Freedom oggcast that Karen Sandler and I recorded about this topic. ]
I have a strange relationship with copyright law. Many copyright policies of various jurisdictions, the USA in particular, are draconian at best and downright vindictive at worst. For example, during the public comment period on ACTA, I commented that I think it's always wrong, as a policy matter, for copyright infringement to carry criminal penalties.
That said, much of what I do in my work in the software freedom movement is enforcement of copyleft: assuring that the primary legal tool, which defends the freedom of the Free Software, functions properly, and actually works — in the real world — the way it should.