A work is protected at the moment it is fixed in a tangible medium of expression from which someone can perceive, communicate or reproduce it, such as on a piece of paper, a hard drive, a CD, the back of a napkin, a memory card, a canvas, an audiotape, a videotape or a piece of photographic film. A work that is just an idea in your head is not copyrighted.
Registration of a copyright is not required in order for a work to be fully protected. Copyright is automatic.
 17 U.S.C. § 102.