Stealing. Illegal because of values. Why? Who can own anything anyway? It's not that everything belongs to everyone. Nothing belongs to anyone! Who said anyone could own anything? Why can one government take what another cannot? Because of value sthough, we decided that the world cannot exist without people "owning" certain things (and that effort should be rewarded with "ownership"), and then taking what already "belongs" to someone else, without permission, became known as "stealing". However, once stealing became agreed upon by most people, it became something that was logically defined. People rarely use values to justify circumvention of stealing (except, perhaps in cases such as Robin Hood).
Copyright (and patents). Illegal because of logic. Why? People need copyright to protect their work, and to inspire effort so it has a payoff, and so that the holder can make a living. Most people agree to it is essence, but its extent is defined by personal values (even if codifed in law). People, though, rarely use logic to justify circumvention of copyright (unless something like its in a court), but rather, use values to circumvent.
But then again, Copyright is an extention of stealing....odd.