Sharing content hardly involves ethics. It's more about economy.
EDIT:
What I meant is, it's not ethically wrong per se; it's only considered bad because it's bad for the economy in the long run.
I wanted to make a point. Defending that point would take essays, which I'm not in the mood to write right now.
Refer to RMS's essays:
http://www.gnu.org/philosophy/misinterpreting-copyright.html
http://www.gnu.org/philosophy/reevaluating-copyright.html
The only 'questionable' act involved in sharing is violating copyright. I don't think of that as a crime or even as an ethically questionable act.