Specifically, Microsoft on May 27, 2003 obtained patent number 6,571,390 from the United States Patent and Trademark Office for their invention--that's their government-legitimized claim--entitled "Interactive entertainment network system and method for customizing operation thereof according to viewer preferences."
Indeed, judging by the summary description included in the patent filing, it looks like Microsoft may have locked up rights to any system which offers up time-shifted movies or television programs over cable, broadband, or satellite systems. (The industry calls programming which customers can start up from the beginning at any time via their cable box "video on demand.)
http://www.embeddedwatch.com/wolfemi...usivemay31.htm