Although patents assignments are registered at the USPTO, state law "governs the question of who has legal title." Despite an earlier Texas court judgment on this issue, AOL challenged MyMail's ownership of its patent -- alleging fraud. On appeal, the CAFC sided with the patentee, finding that the earlier Texas judgment settled the matter. This decision should be seen as contrasting challenges to patent ownership (where prior decisions hold weight) with challenges to patent validity (which can be repeatedly challenged despite prior judgments affirming validity).
Based on a claim construction of the coined term NSP, the appellate panel also affirmed the lower court's summary judgment of noninfringement.