NGA is unlikely to be called upon for surveillance of an individual inside the United States. "NGA imagery is not what you would use to track people," he said. But as the intelligence infrastructure, including the kinds of local camera-surveillance systems that proved so useful in identifying the perpetrators of the London subway bombings, expands in the United States, it raises the specter of a nationwide surveillance web. "These networks are going to get denser and going to cover more area over time," Pike said. "At some point in time somebody's going to drop in an automated face-print recognizer, and then they're off to the races. Anybody who is currently wanted by the authorities, well, there's just going to be parts of the country where such a personcould not enter."

The expanding role of U.S. intelligence agencies on the home front raises serious issues, according to Army Lt. Gen. Russel L. Honoré, the commanding general on the scene in the Gulf Coast during Hurricane Katrina. Last fall, during a national conference on geospatial intelligence, he said, "Most of our capability [in the military] is kept on the classified side because that's the best way to fight the enemy." But the situation in the Gulf Coast, as the lines blurred, was complicated by conflicting policy directives. There were some people in government saying, "You're not going to use the intel stuff on us," Honoré recalled, while others were saying just the opposite: "Why aren't you using that intel stuff to tell us what's going on down there?"