Coca-Cola has built a very valuable business on a secret beverage recipe. To the extent that the Internet spreads, there will be no more secrets in that sense. To preserve shareholder value, it had better turn out that way because they've outsourced everything else, specifically production and distribution. Laws allowing private ownership of property have depended on individual or legal force, often violent. A thief gets his hand cut off.
Laws allowing private ownership of intellectual property are only a couple of hundred years old.
Many people misuse the term copyright as a euphemism for private or secret. In the old days, copyright was a simple matter. Copyright is a relatively enforceable proposition when you're talking about physical stuff. It's difficult to make good, physical duplicates, so copyright owners have a chance of detecting counterfeits, tracking down the copiers, proving that their rights were infringed, and stopping the copying. By the same token, physical copies have actual value, in proportion to their scarcity.