She suspected her husband was cheating on her and that the proof was buried inside the family computer--but how could she get at it? "I installed the program on the machine and had my answer within 24 hours," says the jilted wife who preferred to remain anonymous. Her answer turned out to be "that he was indeed having a physical affair with this girl."

"You are smart and funny and fun to be with and magnificent in bed," his wife read aloud. The words were recovered by new software technology that can retrieve every piece of information on a computer: e-mail, memos, personal financial data and electronic images.

This program, called Spector, runs quietly in the background, taking snapshots every few seconds of the computer screen, then stores them for later inspection.

Enter your password, and all the information, incriminating or not, pops up on the screen. And the person you are spying on never knows.

Cyber-surveillance is everywhere. Governments used to be the only ones that did it but recently the new technology has created a cottage industry: companies that can recover almost anything from your personal computer.

"Your computer files are stored on your computer just like the pages of a book with a table of contents," says Jim Reinert of OnTrack Data, Inc. "When you press the delete key, all that's removed is the table of contents. The pages are still out there."

In this brave new world of cyber-spying, very little is private and whatever you write, even in your own home, may come back to haunt you.

Governments all over the world have become embroiled in controversy about electronic surveillance of the Internet. In the United States, a political storm has arisen over a new FBI Internet tapping system codenamed Carnivore.

In the Netherlands, the Dutch security service BVD admitted that it had been collecting e-mails sent abroad by companies. Dutch laws are being prepared to allow the Justice Ministry to tap into e-mail and subscriber records, scan messages and mobile phone calls, and track users' movements.

In Australia, law enforcement agencies are not required to obtain a court order to demand disclosure of information provided it is in the course of a criminal investigation or is part of an ASIO (Security Intelligence) operation against a threat to national security.

These developments are no coincidence, but the direct result of secret planning over seven years by an international coordinating group set up by the FBI. Under the innocuous title of the International Law Enforcement Telecommunications Seminar, the group has met annually to plan for and lobby to make telecommunications systems "interception-friendly."

A month ago, the European Parliament appointed 36 parliamentarians to lead a year-long investigation into Echelon--the codename for a mainly U.S. system for monitoring traffic on commercial communications satellites.

French politicians and lawyers have taken the lead in accusing the U.S. and Britain of using their electronic intelligence networks to win business from foreign rivals. U.S. politicians have riposted that France runs a worldwide electronic intelligence system of its own--Frenchelon, and includes an eavesdropping station in New Caledonia in the Pacific.

Electronic eavesdropping has also become a battleground between the U.S. and Russia. The Russian-American Trust and Cooperation Act of 2000, passed on July 19, prohibits the U.S. President from rescheduling or writing off billions of dollars of Russian debts unless a Russian spy base in Cuba is "permanently closed."

This base at Lourdes, located near Havana, was the former Soviet Union's most important intelligence facility. It uses Echelon-type systems to collect data from telephone calls and satellite links covering the U.S.

Britain is no laggard in intelligence gathering. The Regulation of Investigatory Powers Act has just extended telephone-tapping powers to cover Internet service providers, and allows the government to arrange indiscriminate tapping or e-mail interception for foreign police forces and security agencies. By the end of the year, the Government Technical Assistance Center will have begun operations from inside MI5's headquarters. Its primary purpose will be to break codes used for private e-mail or to protect files on personal computers. It will also receive and hold private keys to codes which British computer users may be compelled under law to give to the government.

The development of the Government Technical Assistance Center has been pioneered by the Home Office's Encryption Coordination Unit, which says that the center will "provide the capability to produce plain text/images/audio from lawfully intercepted communications and lawfully seized computer media which are encrypted."

MI5 was not normally permitted to encroach on domestic communications. Now, the Regulation of Investigatory Powers Act says that because many domestic Internet communications travel on the same "trunks" as external communications, it will be allowed to trawl through these messages without restriction.

The FBI has just been granted $85 million for an electronic surveillance program called Digital Storm. This foresees the quadrupling of telephone tapping in the U.S. over the next decade. The FBI hopes to build in automated transcription and translation systems.

According to its budget application for the next U.S. fiscal year, a related program called Casa de Web will include central computer archives for intercepted audio and data reports.

Parents in Germany will soon be able to keep track of their children with satellite-linked equipment that works on the same basis as devices used to locate stolen cars.

A device the size of a cigarette packet can be put in a child's satchel or clipped to a belt. Parents will be able to tell almost exactly where a child is, and will be alerted by a telephone call if the youngster strays beyond the limits of predefined areas fed into a computer.

Ingo Brunn, a German engineer who owns the company which devised the system, known as Kid Track, said it would stop parents worrying unnecessarily about their child's whereabouts. Mr. Brunn explained: "Parents can tell Kid Track where their child is allowed, and they will know within 15 seconds if the child strays from that area.”

The system can be reprogrammed to scan new "permitted areas" when a family goes on holiday. Users will be charged a monthly fee of just under £15.

Scientists are offering to replace the twitch of the net curtain next door with a satellite surveillance system that will provide the ultimate way to snoop over the garden fence.

For less than £100, people will be able to spy on their neighbors using cameras in the sky that beam live pictures to their internet screen.

The system, using up to 12 satellites orbiting Earth, will enable subscribers to look at anything from the house next door to a nudist colony or a terrorist training camp in Libya.

While it might tell you if the folk next door have dug a swimming pool, keeping up with what the Joneses are not wearing while sunbathing will not be so easy. The maximum resolution will be about 2.5 meters.

The spy system has been christened, rather darkly, Orwell. Because it operates by radar, it is unaffected by cloud or darkness. The radar-based system's main advantage over existing satellites is that it will offer constantly updated pictures of the Earth's surface every two hours.

At present anyone can pay for a picture from space showing almost any spot on Earth, but by the time it is received it is likely to be several weeks old. If the weather is poor, optical systems cannot take pictures at all.

TOKYO--The multitude of cameras, some described innocuously as "security cameras," send an unmistakable signal: Big Brother is watching you.

The pedestrian bridge over Showa Avenue in Tokyo's Ginza area is a state-of-the-art design, complete with escalators. But they are not the only novel feature of this overpass. From above, one ever-watchful eye keeps pedestrians on the ascending staircase in constant view; another, at the foot of the bridge, confronts those on their way down.

An intercom has been installed beside the camera, and one unsuspecting boy was taken aback when a disembodied voice suddenly warned him not to tamper with an escalator's operating switch. It will come as no surprise to most of us that cameras televise people in public places. In other words, we are monitored by others all the time, everywhere.

As of last August, 295 crossings in Tokyo were equipped with closed-circuit TV cameras, and their images were monitored around the clock from the Traffic Control Center.

The railway company has installed 3,000 cameras throughout the capital. The same goes for subways. Teito Rapid Transit Authority has 900 cameras operating at its 150 stations. The Tokyo metropolitan government is said to have 400 cameras throughout its building. Electronic "seeing eyes" are also prevalent these days in privately owned businesses. Last December the National Police Agency released figures confirming the presence of security cameras at more than 90 percent of banks, credit unions and credit societies; and 94 percent of convenience stores and other late-opening stores. Hotels, karaoke bars and video parlors have followed suit.

Some say it is not far-fetched to talk with real foreboding of the kind of society depicted by the novelist George Orwell in "1984" or by the American film "Enemy of the State." We are already living in it, they warn.

In a crime-plagued part of southeastern Los Angeles County known as Willowbrook, the steady beat from police helicopters can make it seem as though Big Brother is always watching. Maybe not, but under a new surveillance program, county police are always listening.

The Los Angeles County Sheriff's Department has hidden microphones on utility poles and rooftops in a 1-square-mile area as part of an experiment. The microphones pick up loud noises, such as gunshots and exploding fireworks.

They are linked to a computer system that can pinpoint the origin of such sounds to within 20 feet in 7 seconds. The system alerts police dispatchers, who then can send officers to the scene and have a computerized phone system call residents in the area to ask them about the gunfire.

Residents don't seem to mind the microphones, but the surveillance has drawn criticism from privacy advocates, who wonder whether the microphones are picking up more than just gunshots, firecrackers and other loud noises.