The Federal Circuit has recently stiffened the requirements for proving infringement of a “split” method claim — one where no single entity directly performs all the steps of the claim. Such claims, such as those addressed in last month’s decision in Akamai Techn., Inc. v. Limelight Networks, Inc., list a number of steps, not all of which are performed by the alleged infringer. For example, one or more steps listed in the claim might be performed by a subcontractor or a customer.

The Akamai patent concerned the storage and delivery of discrete portions of website content. Limelight did not perform all the steps of the patent, as one of the steps was to be performed by customers. The customers had to “tag” web content that was to be handled a certain way, and Limelight then served the content in a more efficient way.

We have learned from earlier cases that, to establish liability, a patent owner must show that an alleged infringer has performed all steps of a patent claim. Alternatively, to establish “joint liability,” the patent owner must prove that any steps not performed by the alleged infringer are performed as part of an agency relationship or under the “direction or control” of the alleged infringer, such that the actions can be legally attributed to the alleged infringer. BMC Resources, Inc. v. Paymentech, L.P. (Fed. Cir. 2008).

Contracting with someone else to perform such steps would meet these requirements, but the law had been unresolved as to whether merely providing instructions, such as to a customer, would suffice where the customer was not under any legal obligation to perform the steps. In finding no infringement in BMC Resources, the Federal Circuit pointed to the lack of “evidence of instructions or directions,” implying that such evidence could establish the “direction or control” test for infringement.

The Akamai case closes the door on that option, making clear that mere directions or instructions to another entity — absent a legal obligation of that entity to perform the steps — is insufficient to establish infringement of a split claim.

There was a contract between Limelight and its customers providing that the customer was responsible for performing certain of the steps if they wished to use Limelight’s services — but no obligation to actually perform the steps. This, the court said, fell short of establishing Limelight’s control over the customer with respect to the steps, and thus of proving infringement.

As in earlier cases, the court put the blame on the drafter of the claims. The problem “can usually be offset by proper claim drafting. A patentee can usually structure a claim to capture infringement by a single party.” Because Akamai drafted claims that “require the activities of both Limelight and its customers for a finding of infringement,” it “put itself in the position” of having to prove the customer’s actions “were attributable to Limelight.” Because it could not meet this burden, no infringement was shown.

Here is yet another instance of the courts’ tightening the requirements for enforcing a patent and holding the patentee to a stricter interpretation of its claims. It is also a warning to patent practitioners to be increasingly careful in writing claims.