In December, 2010, the Court of Appeals for the Federal Circuit clarified the rules governing joint infringement in Akamai Technologies, Inc. v. Limelight Networks, Inc. (slip opinion) Under the Akamai holding, in order for joint infringement to occur, an agency relationship must exist between the parties. An agency relationship requires that both parties consent that the agent is acting on the principal’s behalf and is subject to the principal’s control. It is insufficient for one party to provide instructions to the other party or for one party to reap benefits from the relationship. Parties who find it difficult to prove a relationship between two parties acting in such close concert and coordination/direction that one is effectively serving as the alter ego or direct delegate of the other post-Akamai will find little sympathy from the courts in arguing a theory of joint infringement.

Courts have historically struggled to give credence to allegations that a plurality of defendants conducting different acts or providing different components for a service or article that was alleged to infringe “as a whole” could be held jointly liable. The source of this struggle arguably begins with the Patent Code, which in Section 271(a) provides that “whoever without authority makes, uses or sells any patented invention, within the United States during the term of the patent therefore, infringes the patent.” To many, this language implicitly or explicitly requires that a singular economic actor or perpetrator (or something or some combination very similar to one) be shown to have violated all the elements of a claimed invention. See BMC Resources v. Paymentech LP, 498 F.3d 1373, 1378–79 (Fed. Cir. 2007).

The patent claims in Akamai involved Content Delivery Networks (“CDNs”). In particular, Akamai’s patents covered a method that included steps encompassing the hosting of CDN servers and the tagging of elements on a webpage. Slip Op. at 7. Limelight, Akamai’s competitor, hosted CDN servers but did not tag any webpage elements. Slip Op. at 8. Instead, Limelight instructed its users to tag elements on their own webpages if they wanted to use Limelight’s CDN servers. Id. Akamai sued Limelight on a joint infringement theory arguing that Limelight and its users should be seen as one actor because Limelight controlled and directed the users to perform the tagging step. Slip Op. at 9. The district court found for Limelight and Akamai appealed. Slip Op. at 10–11.

The Federal Circuit affirmed the district court holding that joint infringement requires the finding of an agency relationship, which did not exist between Limelight and its users. Prior to Akamai, joint infringement could be found if one party “controll[ed] or direct[ed]” the activities of another party, however, simply controlling access to a system and providing instructions on how to use that system were not sufficient to show joint infringement. Slip Op. at 9–10. The court stated that implicit in the pre-Akamai standard was the existence of an agency relationship, which required both parties to consent that the agent is acting on behalf of the principal and is subject to the principal’s control. Slip Op. at 13–14.

Even though Limelight instructed its users to tag web elements as a condition of using its systems, this agreement did not create any obligations for the users to act. Slip Op. at 16. Furthermore, the fact that Limelight derived benefits from its users following Limelight’s explicit and detailed instructions was insufficient to show joint infringement. Slip Op. at 13–14, 16. Therefore, the actions of Limelight’s users could not be attributed to Limelight, which meant Limelight could not be held to infringe Akamai’s patents because it did not perform the step of tagging elements in webpages.

The agency-relationship standard for joint infringement makes it more difficult to prove joint infringement at trial. The court recommends correcting existing claims that require multiple parties to infringe through seeking a reissue patent. Despite this recommendation, attorneys and agents should, for maximum safety, be careful to include claims that do not require aggregating the activities or contributions of multiple parties to establish infringement from the outset. The court stated that it believes joint infringement can be avoided entirely because a “patentee can usually structure a claim to capture infringement by a single party.” Slip Op. at 17. A litigant will receive little sympathy from the court if he fails to prove joint infringement at trial.