This came up in a conversation on rec.arts.sf.composition lately, and I wanted to record it here because it's seems like a very sensible way of looking at the matter -- much more so than ways I'd previously seen. It's from Erol K. Bayburt (with quote from David Friedman left in for context), in a thread entitled "Re: Second Person" (yes, there was much topic drift), posted 03 Mar 2005:
Perhaps there is some value to seriously looking at the question of "how can this be stolen if you still have it?", rather than merely dismissing it as irrelevant. This seems a good answer; property violations don't have to be theft to be violations.
>Surely you have seen the same pattern in discussions of copyright
>violation? There too, the routine defense is "copying his book doesn't
>hurt him--he still has the book." And there too, to some people it is
>obvious that intellectual property is the moral equivalent of physical
>property, and violating it the moral equivalent of theft, and to some
>people it is obvious that it isn't.
To me, violating IP rights is much more akin to *tresspass* than to
theft - still a property rights violation, but a different one.
Calling it "theft" weakens the case, IMO, while the analogy to
tresspass allows one to talk sensibly about the IP equivalents of
right-of-way, squatting, etc.