Ideas are not protected by copyrights. If you tell me about your idea, we both have it. Nothing was taken from you.
If I take your pen, you no longer have it; thats theft.
If I take your pen, you no longer have it; thats theft.
Other than that, you don't lose your right to exploit your work. Someone else is exploiting your work in addition to you. They are infringing on your copyright, not stealing it.
You could sue for everyone for copyright infringement. (This didn't work so well for the RIAA.)
Or you can figure out a way to capitalize off the reason why everyone likes your work.
In any instance you don't lose your copyright.
The two are close, but not synonymous. Take photographs: the exclusive first-use of a photograph is a big thing. If you publish my picture without my permission, my right of control is gone.
I can use copyright laws and the courts to try and get economic redress for that, but nonetheless I no longer have the ability to decide where and when that picture is first published; the ability was stolen from me.
Copyright doesn't prevent copying, it just gives you a way of redress.
It is deprivation of exclusivity though, I agree.
If we do, what if someone has exclusive knowledge of some algorithm, and then someone else discovers it too? Is he a thief?
The thing that is being stolen is the right of exploitation. That is what copyright protects.