In Akamai Technologies, Inc. v. Limelight Networks, Inc., the Federal Circuit clarified the requirements for establishing joint infringement—a theory of direct infringement that may be used when a single party does not perform all of the steps of a method claim. The decision provides a good reminder to consider "who" is likely to perform each step of a method claim. This analysis can be particularly important in the context of diagnostic and personalized medicine methods.

The Patents At Issue

The patent involved in the joint infringement issue (U.S. 6,108,703) relates to web page content delivery services, whereby a host stores and serves embedded objects displayed on a content provider’s web site. Claims 19 and 34 were the independent claims at issue:

19. A content delivery service, comprising:
replicating a set of page objects across a wide area network of content servers managed by a domain other than a content provider domain;
for a given page normally served from the content provider domain, tagging the embedded objects of the page so that requests for the page objects resolve to the domain instead of the content provider domain;
responsive to a request for the given page received at the content provider domain, serving the given page from the content provider domain; and
serving at least one embedded object of the given page from a given content server in the domain instead of from the content provider domain.

34. A content delivery method, comprising:
distributing a set of page objects across a network of content servers managed by a domain other than a content provider domain, wherein the network of content servers are organized into a set of regions;
for a given page normally served from the content provider domain, tagging at least some of the embedded objects of the page so that requests for the objects resolve to the domain instead of the content provider domain;
in response to a client request for an embedded object of the page:
resolving the client request as a function of a location of the client machine making the request and current Internet traffic conditions to identify a given region; and
returning to the client an IP address of a given one of the content servers within the given region that is likely to host the embedded object and that is not overloaded.

As reflected in the highlighted steps, the embedded objects must be "tagged" in order to be served from the host in accordance with the claimed methods.

Akamai’s Theory of Joint Infringement

Akamai relied on the theory of joint infringement to establish direct infringement by Limelight, because Limelight did not itself tag embedded objects. Rather, Limelight’s customers were contractually required to select and tag the embedded objects that Limelight would host and serve. Limelight also provided its customers with detailed tagging instructions.

Akamai relied on these contractual terms and cited the Federal Circuit’s analysis in BMC Resources, Inc. v. Paymentech, L.P. (Fed. Cir. 2007), where the court stated that joint infringement can be established when one party "control[s] or direct[s]" the activities of another.

The jury reached a verdict of infringement, after which Limelight moved for judgment as a matter of law (JMOL) of non-infringement.

While the case was pending at the district court, the Federal Circuit issued its decision in Muniauction, Inc. v, Thomson Corp. (Fed. Cir. 2008), which held that "an accused infringer’s control over its customers’ access to an online system, coupled with instructions on how to use that system, was not enough to establish direct infringement."

The district court found "’no material difference between Limelight’s interaction with its customers and that of Thomson in Muniauction," and so granted JMOL of non-infringement.

The Federal Circuit’s Statement of Joint Infringement Law

The Federal Circuit began its analysis by emphasizing that "direct infringement requires a single party to perform every step of a claimed method." The court explained that the "direct or control" language in BMC stemmed from legal principles of vicarious liability and the notion that a party should not be able to avoid infringement liability "simply by contracting out steps of a patented process to another entity." The court explained that the relationship between the parties must be "such that acts of one may be attributed to the other."

This court therefore holds 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.

Applying this test to the case before it, the Federal Circuit found no joint infringement:

  1. The Federal Circuit found that the tagging instructions that Limelight provided to its customers did not create an agency relationship. In particular, the court found no evidence that Limelight had any right to control its customer’s actions. 
  2. The Federal Circuit found that Limelight’s customer contracts did "not obligate [its] customers to perform any of the method steps. It merely explains that the customer will have to perform the steps if it decides to take advantage of Limelight’s service."

The court concluded that Limelight’s customers "acted principally for their own benefit and under their own control" and so their actions could not be attributed to Limelight.

A Problem of Claim Drafting?

The Federal Circuit decision includes a discussion that raises red flags for patent practitioners:

While acknowledging the difficulty of proving infringement of claims that must be infringed by multiple parties, this court has noted that such concerns “can usually be offset by proper claim drafting. A patentee can usually structure a claim to capture infringement by a single party.”

The court noted:

Here, the asserted claims were drafted so as to require the activities of both Limelight and its customers for a finding of infringement. Thus, Akamai put itself in a position of having to show that the allegedly infringing activities of Limelight’s customers were attributable to Limelight.

Of course, we do not know why these claims were drafted this way, and it can be too easy to second-guess any claiming strategy with 20/20 hindsight in view of an unfvorable court decision!

A Problem Of Infringement Theory? 

The Federal Circuit decision notes that Akamai "waived any assertion of indirect infringement before trial." Thus we do not know whether Akamai might have been successful with a claim of contributory infringement or induced infringement. On the other hand, even contributory infringement and induced infringement usually require that someone was a direct infringer.

Questions for Diagnostic & Personalized Medicine Method Claims

Akamai brings to mind a discussion in the Federal Circuit’s recent decision in Prometheus Laboratories, Inc. v. Mayo Collaborative Services. Prometheus’s claims were directed to

1. A method of optimizing therapeutic efficacy for treatment of an immune-mediated gastrointestinal disorder, comprising:
(a) administering a drug providing 6-thioguanine to a subject having said immune-mediated gastrointestinal disorder; and
(b) determining the level of 6-thioguanine in said subject having said immune-mediated gastrointestinal disorder,
wherein the level of 6-thioguanine less than about 230 pmol per 8×108 red blood cells indicates a need to increase the amount of said drug subsequently administered to said subject and
wherein the level of 6-thioguanine greater than about 400 pmol per 8×108 red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject.

(Not all claims recited the "administering step.)

The Federal Circuit acknowledged that "the final ‘wherein’ clauses are mental steps and thus not patent-eligible per se," but reasoned that "when viewed in the proper context, the final step of providing a warning based on the results of the prior steps does not detract from the patentability of Prometheus’s claimed methods as a whole." The court continued:

No claim in the Prometheus patents claims only mental steps. Therefore, contrary to Mayo’s assertions, a physician who only evaluates the result of the claimed methods, without carrying out the administering and/or determining steps that are present in all the claims, cannot infringe any claim that requires such steps.

Viewing this passage through the lens of Akamai raises several questions:

  • Who would perform each of the method steps of Prometheus’s claims?
  • If the patient self-administers the drug, does he or she do so as an agent of the doctor?
  • If a lab determines the metabolite level, does it do so as an agent of the doctor, or under a contractual obligation to do so?
  • If a doctor orders a test from a lab to determine the level of metabolite, does the doctor do so as an agent of the patient, and the lab do so as an agent of the doctor or under a contractual obligation to do so?
  • Do the requirements for induced infringement or contributory infringement need to be satisfied to find a lab (or test kit manufacturer) liable for infringement (as Mayo was)?
  • Would you chose the doctor or the patient as the underlying direct infringer?