Copyright law. And in Europe at least a deeper moral right to be identified as the author of a work and to have a say in how it's used. For example, I would be very upset if my work was used in advertising, or a political campaign that I violently disagreed with. It's not a black and white issue and that's why this went to the lawsuit stage.

"bits" is a very disingenuous way to look at creative work. The end product is "just" 1s and 0s in the same sense a Porsche is "just" atoms.

So, if I took a picture with a magic camera, that "copied" a Porsche, and magically "pasted" another one in reality, I should have to pay for it again? I mean, this is already an issue with 3d printers and small items. It'll happen with larger ones soon enough.

I understand a little under a decade of copyright protection when you had to horse and buggy your manuscript to a printer and they shipped it by train and boat around the nation to salesmen who again went by train or carriage to sell it... But in the world of one-click publishing? A hundred years plus? Really?

The window of protection is now less a window, and more a gaping wound in the side of creativity, as seen here.

Even without the magic printer, you'd probably be stepping on a number of patents by reverse engineering a Porsche (not to mention copyright/trademark infringement for things like the emblem). You could still be found to be infringing upon patents if you were only using the duplicates for personal use (IANAL, though).

As far as the length of copyright (which, I agree, is currently too long), you can thank Disney for that.

This would be like making a Porsche out of Legos for an art project and then getting sued. No one is confusing one with the other.