NEW YORK -- Cross the U.S. border in a few years, and a hidden camera may zero in on you from 150 metres away, able to recognize you by the shape of your face, perhaps by the telltale markings of your eyeball or even in the way you walk past the border guard.

In milliseconds, a supercomputer would sift through a massive "data warehouse," able to dip into your life: Credit-card purchases, travel patterns, health and banking records would all be scanned. Your old telephone conversations -- in any language -- would be instantly available, along with e-mails that you sent years ago.

It may seem a far-off Hollywood fantasy; indeed it sounds strikingly similar to Minority Report, the Steven Spielberg film in which all U.S. citizens live under constant computer surveillance.

But under the Homeland Security Act awaiting U.S. President George W. Bush's signature, a top-secret Pentagon program known as Total Information Awareness hopes to have such a system ready as early as 2004, potentially giving Uncle Sam the powers of Big Brother, the omnipresent state in George Orwell's 1984.

"It's the most extensive surveillance program in history," said Gabe Rottman, a spokesman for the American Civil Liberties Union, which is trying to derail the plan. "It's unprecedented. . . . Anything you want to know about anybody, you will find out.

"While the promoters of this Orwellian program have argued that such snooping should be accepted as part of the war on terrorism," the ACLU adds in a background paper, "it is clear that this proposal goes too far."

In fact, it is much more than a proposal.

The Pentagon's Defence Advanced Research Projects Agency, which pioneered groundbreaking technologies such as the Internet, supercomputers and stealth cloaking devices to render fighter jets and bombers nearly invisible to radar, has created an office to carry out what is known as data mining.

The Information Awareness Office, equipped with a $200-million (U.S.) startup budget and a logo that shows an all-seeing eye perched on a pyramid, staring down at planet Earth, is at work under the Latin motto Scientia est potentia (knowledge is power). Created after the Sept. 11 attacks, the office promises to build "revolutionary technology" to carry out unparalleled background checks and an assessment of someone's "lifestyle patterns," to try to pinpoint future terrorists.

Under the auspices of the Homeland Security Act, the Information Awareness Office hopes to give U.S. intelligence a computer system that can dig into commercial and government files, a fusion of public and private data never before achieved.

A system is being planned to instantly translate telephone conversations in foreign languages -- Arabic and Mandarin are singled out as priorities -- that will produce transcripts that could be analyzed by the computer.

"In all cases, terrorists have left detectable clues that are generally found after an attack," the office states on its Web site. "To fight terrorism, we need to create a new intelligence infrastructure -- that data base envisioned is of an unprecedented scale."

While most U.S. politicians have supported the idea of such a tool after last year's deadly terrorist attacks, it remains unclear what will be done to protect individual privacy. Civil libertarians and politicians of all stripes have qualms about the project's chief architect: retired Rear-Admiral John Poindexter, a man complicit in past intelligence cover-ups and violations of the U.S. Constitution.

A decade ago, Adm. Poindexter was convicted of five felony counts for lying to Congress under president Ronald Reagan during the White House's Iran-contra scandal, in which the admiral secretly sold missiles to Iran and used the profits to fund Nicaragua's contra rebels. The former national security adviser was sentenced to six months in jail for the illegal operation, though he was acquitted after a higher court ruled he was protected by an immunity deal in return for testifying.

"In some ways, Poindexter is the perfect Orwellian figure for the perfect Orwellian project," said Jonathan Turley, a constitutional-law expert at George Washington University.

"As a man convicted of falsifying and destroying information, he will now be put in charge of gathering information on every citizen. What is most astonishing is the utter lack of public debate over this project."

That debate, however, is heating up.

Since the 1970s, the United States has created dozens of laws aimed at protecting citizens from spying by government agencies. Congressional committees also have a tradition of overseeing the operations of the government's spy apparatus, such as the Central Intelligence Agency, although often in secret. As well, U.S. law has generally made it necessary for the government to get court orders to see bank records or listen in on communications, laws that may apply to data mining.

Since Sept. 11, however, the White House has pushed through the Homeland Security and U.S. Patriot acts, sweeping laws that are challenging those privacy protections. For example, a U.S. court ruled this month that under the Patriot Act, the Federal Bureau of Investigation can now work in concert with the CIA and other agencies, making it easier to get wiretaps.

"As of today, the Attorney-General can suspend the ordinary requirements of the Fourth Amendment in order to listen in on phone calls, read e-mails and conduct secret searches of Americans' homes and offices," ACLU spokeswoman Ann Beeson declared after the ruling. It is unclear whether there will be an appeal.

Also unclear is how members of Congress will be able to oversee domestic surveillance and the reach of data-mining technologies under the new Homeland Security Department, which is being created by the most massive reorganization of the U.S. government since the 1950s.

"The whole system is very confused right now," said Chris Hoofnagle, an expert with the Washington-based Electronic Privacy Information Center. He said Congress must come to terms on "what limits will be on homeland security and data mining."

If not properly policed, he said, innocent individuals -- perhaps those who like to pay cash, or buy one-way plane tickets or buy carpets in Pakistan -- may find themselves deemed suspicious in a computer system looking for irregular patterns. That could cause them to end up on data bases that may make it difficult or impossible for them to fly or get government jobs.

"This could change the presumption of innocence in the United States," Mr. Hoofnagle said, adding that surreptitious cameras will also shred another basic freedom: "When you appear in public people can see you, but you have the right to be anonymous." William Crowell, a software engineer who is on a Pentagon task force on terrorism and deterrence, said the scientists developing data mining are concerned about protecting privacy rights. He said they realize that such technology is not infallible and that it must be guarded from abuses. "Quite frankly, the fact we are having this debate is a testament to the strength of our system, that we aren't going to use the technologies irregardless of the consequences," he said.

The Pentagon's Big Brother plan

The U.S. Homeland Security Act includes plans to set up a system to 'mine' data sources to try to head off terrorists. Critics say it would go too far in invading citizens' privacy.
AN INTERNATIONAL POOL

The pool of information could be worldwide and might include details such as banking transactions, education and medical records, travel history and physical identification files.
U.S. DATA REPOSITORY

A Pentagon office would be a central repository for the information, using 'revolutionary technology' to assess patterns in the data.
DETECTION, RECOGNITION AND ANALYSIS

U.S. intelligence agencies, overseen by Congress, would have access to the system and follow up on the leads it generates.
SOURCE: INFORMATION AWARENESS OFFICE