Commil USA v. Cisco Systems, Case No. 12-1042 (Fed. Cir. June 25, 2013)
The Federal Circuit effected a major change in the law of vicarious liability for patent infringement. In particular, the Federal Circuit has established a defense to induced infringement based on a good-faith belief by the infringer that the patents were invalid. This will likely make obtaining an opinion of counsel on invalidity even more important for those facing patent infringement suits – a well drafted opinion of counsel finding that asserted patents were invalid will greatly reduce the possibility of damages up to a determination of validity at trial, or at a minimum, a denial of summary judgment on invalidity.