Chamberlain Group, Inc. v. Skylnk Tech., Inc. 381 F.3d 1178 (Fed. Cir. 2004) Chamberlain made garage door openers. Each opener used a unique 'code' between the transmitter and the opener for security. Skylink made replacement garage door opener transmitters. They could be programmed to emit any code, so they would work with any garage door opener. Chamberlain sued for copyright infringement. Chamberlain argued that Skylink's product was a device intended to circumvent a technological measure that controls access to Chamberlain's copyrighted 'codes'. Therefore it was a violation of the Digital Millennium Copyright Act (DMCA) (17 U.S.C. §1201(a)(2)), which makes it illegal to manufacture or offer a device to aid circumvention. The Trial Court found for Skylink. Chamberlain appealed. The Trial Court found that since there were no conditions on the sale of their openers, the customer had an implied authorization to access the 'code'. The Appellate Court affirmed. The Appellate Court found that circumvention is defined by §1201(a)(3)(A) as "activity undertaken without the authority of the copyright owner. The Court found that since customers had been implicitly authorized to use the code to open their doors, their activity was not circumvention, and any device Skylink made to help them couldn't be considered a device to aid circumvention. Basically, Skylink's transmitter enabled only legitimate uses of copyrighted code. Therefore it was not covered by §1201(a)(2). Basically, the Court was saying that the DMCA only prohibits forms of circumvention that constitute a threat to other rights under copyright law (like 17 U.S.C. §106). Since Chamberlain didn't have the right to restrict people from using the codes to open their garage doors, DMCA did not give them the right to prevent people from circumventing the copy protection blocking access to the codes. In more technical language, this case said that in order to constitute a violation of §1201(a)(2) a plaintiff must establish that they had ownership of a copyrighted work effectively controlled by a technological measure which has been circumvented so that third parties can now access it without authorization in a way that infringes or facilitates infringement of rights protected by 17 U.S.C. §106, because of a product that the defendant either: Designed or produced primarily for circumvention, Made available despite only limited commercial significance other than to circumvent, or Marketed for use in circumvention of the controlling technological measure.