Last Month at the Federal Circuit
Last Month at the Federal Circuit

January 2011

Agency Relationship or Contractual Obligation to Perform Steps Required for a Finding of Joint Infringement


Judges:  Rader, Linn (author), Prost
[Appealed from D. Mass., Judge Zobel]

In Akamai Technologies, Inc. v. Limelight Networks, Inc., Nos. 09-1372, -1380, -1416, -1417 (Fed. Cir. Dec. 20, 2010), the Federal Circuit affirmed a finding of no joint infringement, holding that Akamai Technologies, Inc. (“Akamai”) did not show that Limelight Networks, Inc.’s (“Limelight”) customers were acting as agents of Limelight when performing the steps of the claim that Limelight itself did not perform.

In an effort to assist websites in efficiently handling large volumes of Internet traffic, Akamai invented a system for allowing a content provider to outsource the delivery of its website content, such as images or videos, collectively known as embedded objects.  Akamai obtained three patents on this technology: U.S. Patent No. 6,108,703 (“the ’703 patent”), U.S. Patent No. 7,103,645 (“the ’645 patent”), and U.S. Patent No. 6,553,413 (“the ’413 patent”).  Limelight operates a competing content delivery service.  But, instead of performing all of the steps for content delivery service itself, Limelight’s contracts with its content provider customers require the customers to perform several steps of the process, including choosing which embedded objects, if any, should be served from Limelight’s Content Delivery Network (“CDN”).  To use Limelight’s service, customers must identify the URL of each chosen object through a process known as tagging, following the instructions provided by Limelight.  Then, Limelight replicates the properly tagged objects on Limelight’s servers and delivers the objects upon request from a web user.  Based on this service, Akamai sued Limelight for infringing several claims of the ’703, ’645, and ’413 patents.    

The only patent at issue during trial was the ’703 patent for which the jury returned a verdict of infringement and awarded $40.1 million in lost profits and $1.4 million in reasonable royalty damages.  After the verdict was returned, Limelight moved for JMOL of noninfringement, arguing that since Limelight itself did not perform every step of the asserted claims, Akamai failed to prove that Limelight directed or controlled the customer’s performance of those steps that Limelight did not itself perform.  The district court granted JMOL of noninfringement in Limelight’s favor. 

On appeal, the Court affirmed.  First, the Court held that Limelight could not be held liable under a theory of joint infringement because it did not direct or control its customers’ actions.  In determining whether Limelight giving instructions to its customers is sufficient to create joint liability, the Court found 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 the acts of one may be attributed to the other.  The Court found that implicit in the applicable joint infringement precedent is “that the performance of a method step may be attributed to an accused infringer when the relationship between the accused infringer and another party performing a method step is that of principal and agent,” or “when a party is contractually obligated to the accused infringer to perform a method step.”  Slip op. at 13.


“[A]s a matter of Federal Circuit law[,] . . . 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.

Under this test, the Court held that Limelight did not infringe the ’703 patent.  In reaching this determination, the Court found that there is nothing to indicate that Limelight’s customers are performing any of the claimed method steps as agents for Limelight.  In analyzing Limelight’s contract with its customers, the content providers, the Court at first recognized that the agreement “requires content providers to perform certain claim steps if they choose to use Limelight’s service,” id. at 17, but stated that “none of those points establishes either Limelight’s control over its customers or its customers’ consent to Limelight’s control,” id

Akamai also appealed the district court’s claim construction of the ’645 and ’413 patents.  The district court construed the term “a given object of a participating content provider is associated with an alphanumeric string” to require that the alphanumeric string include the embedded object’s original URL, defined as the URL including the hostname of the computer on which the actual object resided within the content provider’s domain.  On appeal, Akamai contended that the district court improperly imported the limitation related to the object’s original URL from the preferred embodiment in the specification into the claim construction, thereby unduly limiting the scope of the claims.  Limelight countered that the patents consistently describe “the invention” as associating an alphanumeric string with the object’s original URL.  The Court held that the district court’s claim construction was correct, finding that the URL was not merely discussed as a preferred embodiment but, rather, the written description specifically referred to strings including the object’s original URL as “the invention.”  In addition, the Court explained that the specification as a whole makes clear that including the object’s original URL is the only method described to achieve the claimed association between an alphanumeric string and the embedded code. 

Finally, Akamai appealed the district court’s construction of the claim terms “the given name server that receives the DNS query being close to the client local name server as determined by given location information” and “selecting a given one of the name servers in the content delivery network” to require that the name server be selected by the alternative domain name system.  Akamai argued that the district court improperly incorporated a structural limitation—namely, the alternative domain name system—into method claims.  Again, the Court agreed with the district court’s claim construction.  Contrary to Akamai’s argument, the Court found that method claims often include structural details.  Further, all of the asserted claims in the ’645 and ’413 patents explicitly refer to the alternative domain name system as a detail associated with the claimed method.