In the 2007 movie "Live Free or Die Hard," action hero John McClane, played by Bruce Willis, tries to stop cyberterrorists from pulling off a three-stage systematic attack on a nation's computer infrastructure.

A hacker in the movie explains the concept of a "fire sale," saying: "It's a three-step systematic attack on the entire national infrastructure. Okay, step one: Take out all the transportation. Step two: The financial base and telecoms. Step three: You get rid of all the utilities...that's why they call it a fire sale, because everything must go."

On Wednesday, the U.S. experienced two out of three of the stages described in the movie.

"Automation issues" forced United Airlines to ground all flights Wednesday.

Trading on the New York Stock Exchange was halted Wednesday due to a technical problem. The home page for The Wall Street Journal's web site also crashed Wednesday. "Something did not respond fast enough, that's all we know…" the site said.