According to USA Today, Phillips is seeking patents on technology which will allow broadcasters to block skipping and apparently fast forwarding of all DVR's at any broadcaster's discression.
http://www.usatoday.com/tech/news/techinnovations/2006-04-19-anti-ad-skipper_x.htm
http://www.usatoday.com/tech/news/techinnovations/2006-04-19-anti-ad-skipper_x.htm