Under copyright, you cannot protect an idea; you can only protect the specific expression of the idea. If there is only one way to express your idea, you have a happy situation. If there are other ways to express it, the value (to you) of your original idea is diminished. If someone else has a clearer or more compelling way to express the idea, your copyright probably was not worth much to start with.
Copyright law protects words and images, not concepts. Allowing others to quote you actually protects your original association with the idea; if others are not permitted to quote you (or if your expression of the idea is not in itself quote-worthy), they have to re-describe your concepts using their own words and images, and you stand more chance of losing any association with the idea.
As an author, you can choose to publish your work under a Creative Commons license. This selective assertion of copyright allows anyone else to copy, distribute, display and perform your work, and to make derivative works, so long as the original author is given credit, the use is non-commercial, and any derivation, alteration or extension of the work is only distributed under a Creative Commons license. Creative Commons has become popular among academics and researchers who need to share their work but where concerns about copyright and plagiarism used to hamper the sharing.
An idea unshared has little to no value. The more widespread an idea becomes, the greater its value becomes. Old-school hierarchical trickle-down of knowledge through formal publishing is a slow, expensive, and limiting model for the dissemination of ideas. Today, the networking of ideas using Internet-based vehicles is geometrically faster, cheaper, and more penetrating. And it provides a benefit that was also limited in the past -- an author can get instant feedback from a vast array of sources, making it easier for him/her to polish and improve on the original work.