This capability is called selectable output control or SOC, and the FCC banned it back in 2003. SOC would allow "service operators, such as cable companies, to turn off analog outputs on consumer electronics devices, only allowing digital plugs" such as HDMI. The MPAA is arguing that if they could directly turn those plugs on and off, they could offer more goods to consumers.
But that's not what over a dozen public interest groups think, notes Home Media Magazine:
Groups including Public Knowledge, the Digital Freedom Campaign, the Electronic Frontier Foundation, the Consumer Federation of America and the Media Access Project, are fighting the MPAA over the request, saying it puts control of privately owned consumer electronics into the hands of the movie industry, hurts TiVo and Slingbox owners, and leaves out consumers who own TVs without digital connections.
Consumerist : http://consumerist.com/5400626/mpaa-asks-fcc-for-control-of-your-tvs-analog-outputs