9/11 has indelibly altered America in ways that people are now starting to earnestly question: not only perpetual orange alerts, barricades and body frisks at the airport, but greater government scrutiny of people’s records and electronic surveillance of their communications. The watershed, officials tell FRONTLINE, was the government’s shift after 9/11 to a strategy of pre-emption at home – not just prosecuting terrorists for breaking the law, but trying to find and stop them before they strike.

President Bush described his anti-terrorist measures as narrow and targeted, but a FRONTLINE investigation has found that the National Security Agency (NSA) has engaged in wiretapping and sifting Internet communications of millions of Americans; the FBI conducted a data sweep on 250,000 Las Vegas vacationers, and along with more than 50 other agencies, they are mining commercial-sector data banks to an unprecedented degree.

Even government officials with experience since 9/11 are nagged by anxiety about the jeopardy that a war without end against unseen terrorists poses to our way of life, our personal freedoms. “I always said, when I was in my position running counterterrorism operations for the FBI, ‘How much security do you want, and how many rights do you want to give up?'” Larry Mefford, former assistant FBI director, tells Smith. “I can give you more security, but I’ve got to take away some rights.

Personally, I want to live in a country where you have a common-sense, fair balance, because I’m worried about people that are untrained, unsupervised, doing things with good intentions but, at the end of the day, harm our liberties.”