In Lexmark v. Static Control Components, Lexmark, plaintiff-appellee, sought preliminary injunction against Static Control Components (SCC) defendant-appellant, in the U.S. District Court for the Eastern District of Kentucky, to prevent SCC from distributing its SMARTEK computer chips. Lexmark, a manufacturer of laser and inkjet printers and toner cartridges, designed its toner cartridges with an embedded chip that notifies the printer if the cartridge was refilled by Lexmark. If not, then the printer is designed to reject the cartridge. This dispute involves two computer programs. The “Toner Loading Program,” coded into Lexmark’s toner cartridge chip, calculates toner levels. The “Printer Engine Program,” coded into the memory in the printer itself, controls various printer functions. The Loading Program contains minimal code (only about 45 commands, using 55 bytes of memory). SCC designed its SMARTEK chip such that it mimicked Lexmark’s chip and could be embedded in remanufactured toner cartridges. Lexmark was granted a preliminary injunction in district court on two main theories of liability: (1) SCC’s chip copied the Loading Program in violation of the federal copyright statute; and (2) SCC’s chip violated the Digital Millennium Copyright Act (DMCA) by circumventing a technological measure designed to control access the to the Engine Program. The Sixth Circuit vacated the judgment, finding that Lexmark did not establish a likelihood of success on its copyright infringement claim or on its DMCA claim.The Sixth Circuit applied an abuse-of discretion standard in reviewing the district court’s preliminary injunction. In applying this standard, the Sixth Circuit considered: (1) Lexmark’s likelihood of success on the merits; (2) the possibility of irreparable harm to Lexmark in the absence of an injunction; (3) public interest considerations; and (4) potential harm to third parties. In the context of copyright, the court places particular emphasis on the first factor, “because irreparable harm is presumed once a likelihood of success on the merits has been established.” The Copyright Act, 17 U.S.C. Section 102, grants copyright protection to “original works of authorship fixed in any tangible medium of expression,” including “literary works.” Computer programs are generally entitled to copyright protection as literary works under 17 U.S.C. Section 101. In a suit for copyright infringement the plaintiff (Lexmark) must show (1) ownership of a valid copyright, and (2) that the defendant copied protectable elements of the work. The copyright statute states that “In no case does copyright protection for an original work of authorship extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of … form….” 17 U.S.C. Section 102(b). According to the court, “this provision embodies the common-law idea-expression dichotomy that distinguishes the spheres of copyright and patent law.” Copyright protection is only extended to the expression of the idea, not the idea itself. The related doctrine of merger states that where there is a very limited number of ways to express an idea, “copyright protection does not exist because granting protection to the expressive component of the work necessarily would extend protection to the work’s uncopyrightable ideas as well.” The doctrine of “scenes a faire” similarly states that when external constraints limit the options for expression, copyright protection is precluded. “In the computer-software context, the doctrine means that the elements of a program dictated by practical realities… may not obtain protection.” The Sixth Circuit has previously held that efficiency represents an external constraint in the context of copyrightability of computer programs.