Since the attacks of September 11th, many Americans have been wondering when the next big attack would come. This morning, America woke up to the news that a coordinated attack—what intelligence officials referred to as “the big one”—might have been thwarted.

Time Magazine reports that the “U.S. picked up the suspects’ chatter and shared it with British authorities,” who then rounded up 24 people who were involved in planning simultaneous attacks on 9 different planes:

Their plan was to smuggle the peroxide-based liquid explosive TATP and detonators onto nine different planes from four carriers — British Airways, Continental, United and American — that fly direct routes between the U.K and the U.S. and blow them up mid-air. Intelligence officials estimate that about 2,700 people would have perished, according to the official.

Britain’s MI-5 intelligence service and Scotland Yard had been tracking the plot for several months, but only in the past two weeks had the plotters’ planning begun to crystallize, senior U.S. officials tell TIME. In the two or three days before the arrests, the cell was going operational, and authorities were pressed into action. MI5 and Scotland Yard agents tracked the plotters from the ground, while a knowledgeable American official says U.S. intelligence provided London authorities with intercepts of the group’s communications.

I’m waiting for the media to start demanding answers from our elected officials: Were these intercepts constitutional? Was anyone’s phone tapped? Were warrants necessary and were they obtained properly?

Sure, 2,700 people might have been saved, but at what cost to our principles?