If anything, we should have been asking ourselves what has made music, text, and video different until now. Everyone is well aware of the issues involved when illegally downloading books, movies, and music, and everyone has come to understand that this is stealing, just as shoplifting would be from a bookstore or music store.
So, is it really a stretch to extend these ideas to objects manufactured in a 3D printer?
It was merely a technical/historical anomaly that made it so books, music, and movies could be transferred anywhere electronically, before your your set of china and silverware could be. So now we are beyond that strange little window in time. The same problem has become generalized, and the same rules have to be applied.