exist. Culture ought to be a dynamic accretion of ideas. There is no such thing as a completely new idea. Please, how nave! There are only wonderful, endless manifestations of ideas built on each other, mirroring and referencing each other. Imagine a big open public room. Nothing is confidential. Everyone can see what everyone else is doing. A hundred people come in, stand at easels, grip their pencils. They are asked by a woman at the front to sketch a picture of an apple on a table. They can clearly see each other's work. When they're done, each one owns the copyright to their sketch, but they don't own the idea of an apple on a table. Copyright protects the maker of a work from having it reproduced by someone else. If the best, most beautiful sketch of the apple on the table was scanned by someone and then used without permission, that would an infringement -- rightly so. But to protect the rights of the person who came up with the idea of the apple on the table? Of course not -- that would be totalitarian. What about a person who suggested the apple should be green instead of red, or the person who thought the apple should have a happy looking worm in it? Should they get a credit on someone else's sketch if the other person wants to draw a green apple with a worm? Where do you draw the line? Simple. Ideas want to be free.