With a few narrow exceptions, U.S. patent law concerns itself with activity that either occurs within this country’s borders or crosses its borders. In the typical case, that means that a patentee can recover lost profits or reasonable royalties based on the domestic sales of infringing products. However, patentees have begun to successfully advance a new and creative approach that this Essay labels the “worldwide causation” theory. So long as some domestic infringement can be said to cause sales overseas, patentees argue that there should be no territorial limitation on their recovery, allowing recovery for damages suffered anywhere in the world.
Patent law has long held that laws of nature, natural phenomena, and abstract ideas are not patentable. At the same time, many patents cover applications that grow out of these fundamental concepts. Courts have recognized that such applications are patentable. Observers had hoped that the Supreme Court’s decision in Mayo v. Prometheus would illuminate the line between unpatentable concepts and patentable applications of those concepts. Unfortunately, the recent decision issued by the Supreme Court raises more questions than it answers. Although the Court gave a variety of reasons to explain why Prometheus Laboratories’ (Prometheus) patents were not patent-eligible, the Court’s primary rationale involved dissecting Prometheus’ claim. The Court found that the limitations did not add “enough” to the law of nature that lies at the heart of Prometheus’ invention.
Because the Court never explained what “enough” is, critics have been quick to deride Mayo. One commentator went so far as to say that the decision “creates a framework for patent eligibility in which almost any method claim can be invalidated.” Although I agree with the Supreme Court’s ultimate decision, I am also concerned that its reasoning unnecessarily jeopardizes many deserving patents that have not previously been thought to have any vulnerability under 35 U.S.C. § 101—the federal patent statute that defines what types of subject matter may be patented. By failing to provide a framework for determining when additional limitations can change an unpatentable concept into a patentable application, the Supreme Court has cast doubt on a host of less controversial patents. But the decision does not have to wreak the havoc that many fear it will. There is room for a more restrained understanding of Mayo.