The court noted that although patent eligibility under 35 U.S.C. § 101 is an issue of law, “there is no clarity at this time as to the standard of proof that must be applied to factual disputes that may be intertwined with the issue of eligibility of a particular patent or claim.” Id. at 9. In fact, Districts have applied different standards in addressing patent-eligibility under § 101 – some have treated the issue solely as a question of law, while others have applied a clear and convincing evidentiary burden. See id. at 10-11. The court declined to resolve the dispute over the standard of proof required to invalidate a claim under § 101, but instead explained that the ’050 and ’142 patents are patent ineligible even assuming the court must apply a clear and convince standard.
Intellectual Ventures I LLC v. Symantec Corp., No. 10-1067-LPS, in the District of Delaware (Apr. 22, 2015).