Alexander Cockburn's latest piece at CounterPunch (2/10/12) included this from a tipster:
I was visiting ABC News the other day to see a friend who works on graphics. When I went to his room, he showed me all the graphics he was making in anticipation of the Israeli attack on Iran; not just maps, but flight patterns, trajectories and 3-D models of U.S. aircraft carrier fleets.
But what was most disturbing–was that ABC, and presumably other networks, have been rehearsing these scenarios for over two weeks, with newscasters and retired generals in front of maps talking about missiles and delivery systems, and at their newsdesks–the screens are emblazoned with "This Is a Drill" to assure they don't go out on air (like War of the Worlds).
Then reports of counter-attacks by Hezbollah in Lebanon with rockets on Israeli cities–it was mind-numbing. Very disturbing–when pre-visualization becomes real.
Does that kind of thing actually happen? Well, yeah.
CBS "practiced" covering a U.S. bombing of Iraq back in 1998–and the footage was apparently fed to a satellite (L.A. Times, 2/20/98):
CBS jumped the gun Friday on a possible U.S. attack on Iraq: The network inadvertently transmitted a practice news report via satellite that could be picked up by television stations and viewers with special equipment.
To try out new graphics for combat coverage in the event the U.S. goes forward with the threatened bombing of Iraq, CBS anchor Dan Rather was rehearsing with Pentagon correspondent David Martin over a closed line between CBS's New York headquarters and its Washington news bureau. The report was mistakenly sent up to a communications satellite.