During the course of routine operations, computers temporarily copy programs and other copyrighted material to their random access memory ("RAM"). In MAI Systems Corp. v. Peak Computer, Inc., the Ninth Circuit held that a temporary copy stored in a computer's RAM could constitute an infringement of the copyright owner's reproduction right. In the decade since MAI, numerous other courts have followed the Ninth Circuit's holding. The United States government has also exported this view in several free trade agreements. In June 2004, however, in CoStar Group, Inc., v. LoopNet, Inc., the Fourth Circuit suggested that a temporary copy made by an Internet service provider ("ISP") acting as a conduit of information might not be an unlawful copy after all--at least in some circumstances. This Perspective examines existing law on temporary copies and how it may be affected by the CoStar decision. Click on the banner above for the html version or here for the pdf version.