The new body monitors could, if a driving hazard appeared imminent, trigger the car's safety systems to tap the brakes, turn off a radio, block a cellphone from ringing or take other actions.

WSJ: Designing a Car That Takes Your Pulse, Senses If You're Ill

Ford's MyKey system has been engendering teen resentment since the release of the 2010 Focus, allowing parents to limit max speeds and cap radio volume, but parental control doesn't stop there -- the 2011 MyKey can selectively block radio stations.

ENGADGET: Ford MyKey adds radio censorship to further control teen driving habits

Air traffic controllers say the illegal radio broadcasts often block out vital communications with pilots.

BBC: Ofcom said there were 70 such cases in 2006

Or special wallpaper could be printed which could covertly block radio frequencies, such as mobile phone or Wi-fi (wireless broadband) signals.

BBC: NEWS | Technology | 'Magic ink' that makes metal grow

Starting next year, parents will have the option to block 16 Sirius radio channels from the car's dial, among them Howard Stern, Playboy, and Hip-Hop Nation.

ENGADGET: Ford MyKey adds radio censorship to further control teen driving habits

No matter what part of the normal radio spectrum you pick, you will find some material that will reduce, deflect or block the signal entirely.

FORBES: Got Wires?

With the same fervor that rallied the open-source free software movement, members of such groups as Seattle Wireless, in Seattle, Washington, SFLan in San Francisco and Consume.net in London are bolting radio antennas to their roofs and broadcasting a shared invisible connection to their friends down the block.

FORBES: Digital Spin

In a radio interview on Friday, Howard confirmed that he would not try to alter investment laws to block a takeover of the airline known affectionately as the Flying Kangaroo.

FORBES: Magazine Article