Our surveillance state was born in the brain of Admiral John Poindexter in 1983. Poindexter, President Ronald Reagan's national security adviser, realized that the United States might have prevented the terrorist massacre of 241 Marines in Beirut if only intelligence agencies had been able to analyze in real time data they had on the attackers. Poindexter poured government know-how and funds into his dream - a system that would sift reams of data for signs of terrorist activity. Decades later, that elusive dream still captivates Washington.

After the 2001 attacks, Poindexter returned to government with a controversial program, called Total Information Awareness, to detect the next attack. Today it is a secretly funded operation that can gather personal information on every American and millions of others worldwide. But Poindexter's dream has also become America's nightmare. Despite billions of dollars spent on this digital quest since the Reagan era, we still can't discern future threats in the vast data cloud that surrounds us all. But the government can now spy on its citizens with an ease that was impossible - and illegal - just a few years ago.

Drawing on unprecedented access to the people who pioneered this high-tech spycraft, Shane Harris shows how it has shifted from the province of right-wing technocrats to a cornerstone of the Obama administration's war on terror. Harris puts us behind the scenes and in front of the screens where 21st-century spycraft was born. We witness Poindexter quietly working from the private sector to get government to buy in to his programs in the early '90s. We see an Army major agonize as he carries out an order to delete the vast database he's gathered on possible terror cells - and on thousands of innocent Americans - months before 9/11. We follow General Mike Hayden as he persuades the Bush administration to secretly monitor Americans based on a flawed interpretation of the law.