Kenyon successfully represented Sony Electronics Inc. in a patent litigation suit against Guardian Media Technologies, Ltd. related to V-chip and parental control technology in televisions and DVD players. The US District Court for the Southern District of California ruled in favor of Sony and other consumer electronics companies granting summary judgment of non-infringement on one of two patents-in-suit in consolidated actions against Guardian. Guardian had asserted the now expired patents-in-suit, US Patent Nos. 4,930,158 and 4,930,160, against televisions and DVD players having the capability to block programs based on their ratings. The Court ruled that Sony and the other companies did not infringe the '158 patent literally or under the doctrine of equivalents based on two separate grounds.
Sony initially filed its declaratory judgment action against Guardian in 2005 and, at the same time, requested that the Patent Office reexamine the patents. The district court case became active in mid-2008 after the Federal Circuit reversed the district court's previous dismissal of the case for lack of declaratory judgment jurisdiction, and after the district court's stay pending completion of the reexaminations by the Patent Office, where a majority of the claims were cancelled. Case number 05-cv-1777 (2009).