a CD is property
the software on the CD is information
stealing CD is stealing
copying software on CD is sharing
information can be copied and shared almost effortlessly, while material objects can't be.
That's what I believe.
here is a small essay about the popular way to describe patents and copyright as "intellectual property":
http://www.gnu.org/philosophy/not-ipr.xhtml
On the other way, I think copyright in digital age has also been abused - a book is copyrighted, but you can share your book by lending it to your friend and let him/her copy parts of it with a ink and pen. No one is called as "thief" or "pirate" for this. For software you even must buy multiple copy if you have multiple computers.