Patent Law

Akamai v. Limelight: Joint Infringement Requires an Agency Relationship or a Contractual Obligation

By Jason Rantanen

By Jason Rantanen

Akamai Technologies, Inc. v. Limelight Networks, Inc. (Fed. Cir. 2010)
Panel: Rader, Linn (author), Prost

Three years ago, in BMC Resources, Inc. v. Paymentech, L.P., 498 F.3d 1373 (Fed. Cir. 2007), the Federal Circuit sharply limited the ability of patent holders to assert claims of joint infringement.  Akamai v. Limelight expands on the "control or direct" rule announced in BMC, explaining that joint infringement requires an agency relationship or a contractual obligation to carry out the relevant steps. 

Akamai's Claim of Joint Infringement
Joint infringement issues can arise when a patent holder asserts method claims over activities whose steps are not carried out by a single party.  For example, if a patent claims a method involving performing steps A, B, and C, the patent holder may need to argue joint infringement (as opposed to straightforward direct infringement) if steps A and B are performed by one party and step C is performed by a second party. 

In Akamai, while the accused party (Limelight) performed the majority of the steps of the claim, at least one of the steps was performed by its customers.  The patent, No. 6,108,703, is directed to an improved method for storing web page content.  Conventionally, the entirety of a web page, including both the page itself and embedded content (such as graphics) is stored on a single server, or mirrored in its entirety across multiple servers.  The patents-in-suit claimed a new approach, which involves storing only the embedded objects on mirrored servers (called a "Content Delivery Network," or "CDN"), while having the webpage itself continue to reside on the content provider's servers.  In order to make this system work, the claims further require that the object URLs be "tagged" to resolve to the CDN.  Limelight, Akamai's competitor in the CDN business, performed most of the claimed steps but had its customers tag the URLs.

Because some of the steps were performed by Limelight and some by its customers, Akamai relied on a theory of joint liability, arguing that Limelight controls or directs the activities of its customers.  Following a jury finding of infringement, the district court granted a JMOL of noninfringement.  On appeal, Akamai contended that substantial evidence supported the infringement finding, arguing that Limelight "(1) creates and assigns a unique hostname for the content provider; (2) provides explicit step-by-step instructions to perform the tagging and serving claim steps; (3) offers technical assistance to help content providers with their performance of the claim step; and (4) contractually requires content providers to perform the tagging and serving claims tepees if they utilize the Limelight service."  Slip Op at 11. 

Important holdings
In affirming the district court's judgment of noninfringement, the CAFC expanded on its ruling in BMC that "joint liability may be found when one party 'control[s] or direct[s]' the activities of another party."  Slip Op. at 9.  After noting the foundational nature of this standard, the Akamai panel further held that "what is essential is not merely the exercise of control or the providing of instructions, but whether the relationship between the parties is such that acts of one may be attributed to the other."   Id. at 12.  The court interpreted this as requiring either an agency relationship or a contractual obligation: "as a matter of Federal Circuit law that there can only be joint infringement when there is an agency relationship between the parties who perform the method steps or when one party is contractually obligated to the other to perform the steps."  Slip Op. at 14.

Analyzing the issue as a question of agency law, the CAFC concluded that no substantial evidence supported a finding that Limelight's customers perform any of the steps of the claimed method as agents for Limelight.  The court also rejected Akamai's theory that Limelight's customers are contractually required to perform the tagging step.  Rather, the court stated, the contract does not obligate the customers to perform any of the method steps; instead, it "merely explains that the customer will have to perform the steps if it decides to take advantage of Limelight's service."  Slip Op. at 16.

Note: The court repeated the warning it set forth in BMC Resources, 498 F.3d at 1381, that concerns about the difficulty of proving infringement of claims that must be infringed by multiple parties "by proper claim drafting.  A patentee can usually structure a claim to capture infringement by a single party."  Slip. Op. at 17 (quoting BMC Resources).  Failing this, the court suggested (citing Mark Lemley's Divided Infringement article), that patentees may be able to correct a claim by seeking a reissue patent.

Claim Construction
Akamai also challenged the district court's construction of two claim terms in related patents, contending that both constructions imported limitations from the specification into the claims.  In a fact-intensive analysis, the CAFC rejected Akamai's arguments, concluding that the district court correctly interpreted the disputed terms given the treatment of the invention in the specification and the lack of any contrary evidence in the prosecution history. 

Full post as published by Patently Obvious on December 20, 2010 (boomark / email).