College Copy Shop (CCS) compiles, copies, and sells reading materials to students on the instructions of their professors, who indicate which parts of which publications should be included. These include texts published by Deep Topics, Inc. CCS does not obtain the permission of Deep Topics, or any of the other original publishers of the copied materials, and does not pay royalties on the sales of the compilations, Deep Topics and others file a suit against CCS, alleging infringement of the plaintiffs' intellectual property rights. What is CCS's likely defense