this reminds me of the story Press Enter[] by John Varley. the net ai used people's computer screens to program their behavior. (however, I believe it used a series of flashing graphics rather than EM fields.)

A TV is already a mind-control device. Research has shown that watching TV produces similar brain waves to hypnosis. When you watch TV, you passively absorb all the information without being aware of it. Later, when your brain needs to decide about something, it automatically trawls your mental database for relevant information. Your brain doesn't differentiate between information received from the real world or TV and this information dictates your responses to any stimuli.

Combine this with biased news reporting, mental imagary in shows (drugs are bad, m'kay) etc, you realise we don't have a chance in hell. I thought it was pretty much well known that watching a lot of TV turns you into a brain dead zombie.

Reminiscent of infamous Pokemon Episode #38, but that turned out to be more mass hysteria than anything else:
http://www.csicop.org/si/2001-05/pokemon.html

OLD NEWS ALERT: I don't know about "prior art" but my neighbor's dog thought of this like, 3 years ago so... *yawn*

Causing a "physiological effect" is a loooong way from "mind control", folks. Don't get too hepped up about this yet....

Pretty much the same effect the Tilley sisters used to have on me.

I for one look forward to our new media mind-control overlords.