 The domain of copyright protection is original works of authorship fixed in any tangible medium of expression (17 U.S.C. §102 (1988)). Works that may be copyrighted include literary, musical, artistic, photographic, architectural, and cinematographic works; maps; and computer software. First, for something to be protected, it must be fixed in a permanent or tangible medium of expression.  For example, an expression could be chiseled into stone, printed in a book, or saved on a hard drive. Second, the work must be “original”—the work must be the author’s own production; it cannot be the result of copying (Bleistein v. Donaldson Lithographing Co., 188 U.S. 239 (1903)). Third, copyright does not extend to short phrases, titles, or names as these to do not contain the minimum amount of authorship required by copyright. A fourth requirement that limits the domain of what can be copyrighted is that the expression must be “non-utilitarian” or “non-functional” in nature. Utilitarian products, or products that are useful for work, fall, if they fall anywhere, within the domain of patents. Finally, rights only extend over the actual concrete expression and the derivatives of the expression—not to the abstract ideas themselves. For example, Einstein’s Theory of Relativity, as expressed in various articles and publications, is not protected under copyright law. Someone else may read these publications and express the theory in her own words and even receive a copyright for her particular expression. Some may find this troubling, but such rights are outside the domain of copyright law. The individual who copies abstract theories or ideas and expresses them in her own words may be guilty of plagiarism, but she cannot be held liable for copyright infringement.