Last summer, while my mother was visiting me in the United States, burglars broke into her house in rural England and emptied it of much of what she held most precious. The thieves knew just what they were after, the local bobbies told us as they searched the house for clues. They had carefully removed the most valuable pictures, ornaments and small pieces of furniture. And they were likely to be back with bigger ambitions and a bigger truck.

One of the police recommendations? Install a closed circuit television camera (CCTV) in the house in the hope of getting mug shots of the intruders next time they came to help themselves to my mother's possessions.

Smile, you're on Culprit Camera.

Britain has become the world's premier surveillance society. There are more than 4 million unblinking electronic eyes gazing down on shoppers and travelers across the country (though far, far fewer human brains are dedicated to deciphering the data those eyes record). London's railway stations are overseen by some 1,800 cameras, and another 6,000 are trained on the capital's underground train network and double-decker buses, catching the average commuter on videotape about 300 times a day.

It's the very ubiquity of the technology that brought the world that chilling snapshot of the July 7 bombers sauntering through a station en route to mass murder, as well as the four close-ups of the July 21 terrorists fleeing their botched attempts to redouble the havoc. Yesterday, those close-ups were front-page news again, this time superimposed with the suspects' names and arrest dates.

Some people have agonized about the Orwellian implications of such surreptitious surveillance, indulging in eye-in-the-sky speculation about the invasion of individuals' privacy. Developments such as face-recognition technology and computerized tracking of out-of-the-ordinary behavior have reawakened anxieties about Big Brother. But for the most part, the British have learned to live with -- and sometimes even appreciate -- the ever watchful eye. And, really, it takes a certain hubris, a strain of self-importance, for Mr. and Ms. Ordinary Citizen to imagine that anyone is watching them, anyway.

Who, for heaven's sake, is going to take the time to monitor the monitors? London police initially estimated that they would need a couple of weeks to go through the mind-numbing hours of tape provided to them after the first bombing -- and that would be with the help of special officers drafted for such a high-profile investigation. Think about it: Two weeks worth of nonstop comings and goings -- watching people sit on station platforms, read newspapers, eat sandwiches, scratch their noses, consult their watches, in a kind of life-or-death game of Where's Waldo?

Now consider, if you can bear it for one brief moment, watching "A Day in the Life of Frances Sellers." I wish I could pretend it was more exciting. But even the highlights (allow me a little hubris -- there are some) might seem a bit humdrum if you had to endure them day after day, night after night. It must be much the same with other forms of surveillance. As a journalist friend, who once lived with his young family in an apartment in China that was undoubtedly bugged, put it: Who's going to separate the hours of potty-training talk from the few potentially valuable snippets of conversation? Just imagine the lot of the poor Chinese spying flunky, dedicating every minute of his working life to tuning in to the messy minutiae of my colleague's life.

Practicality aside, the philosophical argument over privacy essentially bit the dust in Britain more than a decade ago when some unforgettable footage made people I know put aside any reservations they'd had. Recorded at 15:39 on Feb. 12, 1993, and later broadcast nationwide, a grainy CCTV picture showed a trusting toddler taking a stranger by the hand and being led out of a Liverpool shopping center. Just days later, 2-year-old Jamie Bulger was found bludgeoned to death on a railway track, bringing horror to the nightly news programs. The camera hadn't prevented the crime, but its imperfect images allowed the police to measure the comparative heights of the child and his abductors. Without them, the police might have been looking for a very different kind of culprit from the two 11-year-old boys who were later convicted in the toddler's murder.

"The Jamie Bulger case was a sea change over here," Peter Fry told me. Fry, who is director of Britain's CCTV User Group, a 600-member association of organizations including local councils and universities that use closed-circuit cameras, says that many people in Britain no longer see the technology as Big Brother but "as a benevolent father." You might expect Fry, in his position, to say that. But in my recent visits to Britain, I've rarely heard people raise objections to CCTV (except -- vociferously -- to the cameras set up to catch speeding motorists; the equipment often ends up being vandalized). And Fry points out that although the technology creates miles of useless footage, it can actually economize on police time. He described to me a pub brawl that ended in a knifing. Thirty people were involved, he said, and the police would have had to take and sift through 30 witness statements, filtering out the effects of inebriation as they divined the truth from 30 differing perspectives. Instead, a half-hour videotape showed just who slit whose throat.

The philosophical underpinnings for CCTV observation lie in the ideas of Britain's 18th-century legal theorist Jeremy Bentham. He had a sort of God's-eye view of moral reform, believing that if people thought they were being watched, they'd probably shape up. Inspired by his brother's effort to design a factory where large numbers of unskilled workers could be supervised by a skilled few, Bentham came up with the concept of a "panopticon" -- a prison where criminals could be watched without knowing exactly when, thus conveying the discomfiting "sentiment of an invisible omniscience." "The more constantly the persons to be inspected are under the eyes of the persons who should inspect them," wrote Bentham, "the more perfectly will the purpose of these establishments have been attained." Bentham's theories are reflected in the design of Philadelphia's Eastern State Penitentiary, where prisoners were left to reflect upon their sins in cells radiating out from a central observation point.

Over the past decade, London has become a kind of urban panopticon, though it's not clear that the constant possibility of being observed has led to better behavior (Britons hardly being the very model of modern moral rectitude). But Fry argues that CCTV indeed deters certain kinds of planned crime (like car theft), even if it doesn't do much to deter spontaneous eruptions (like the pub brawl). And it probably displaces some other kinds of crime (which presents its own moral conundrums, but I hope you won't think me un-neighborly in my wish that the burglars who broke into my mother's house might be displaced -- and choose the big house up the lane next time around).

Americans are, comparatively speaking, camera shy. Of course, video surveillance is widely used in supermarkets and hotel lobbies, but when Washington installed cameras on the Mall in 2002, the questions sparked by civil liberties groups led to their use being strictly regulated. Following the London bombings, though, D.C. Mayor Anthony Williams called for more cameras in parks and commercial districts. Other cities, like Baltimore, have taken advantage of federal antiterrorism funds to increase their surveillance systems in the hope of combating street crime, too. But it's all done against a backdrop of distrust of any kind of official observation, and dispute about how effective the cameras really are.

Still, British authorities have bought into the concept in a big way: CCTV was first used primarily in retail stores but in the '70s and '80s gradually moved into public spaces. In an effort to reduce robberies and assaults, London Underground has been using cameras for about three decades now. Between 1994 and 1997, 78 percent of the government's crime prevention budget was spent on CCTV, according to scholars at the University of Hull in Britain. And cameras have been used to monitor protests and trouble spots such as soccer games, where the police have used a mobile surveillance unit known as the Hoolivan (equipped, one can only suppose, with hoolicams), to keep an eye on rowdy fans and zoom in on known troublemakers.

Even before the July attacks, CCTV had proven its use in solving high-profile acts of terrorism. In 1999, there was a brief reign of terror in London when a series of nail bombs exploded, apparently aimed at the city's black, south Asian and gay communities. By plowing through some 26,000 hours of videotape, the police were able to find pictures of a man carrying a bag as he approached the site of one bombing and leaving without it. They quickly released an image of him. A 22-year-old fascist sympathizer named David Copeland was soon identified by a co-worker and later convicted for the murder of three of his victims.

Some crooks have wised up to the possibility of being caught red-handed, as one detective explained to me when we discussed putting a camera in my mother's house. He once had a lovely video view, he told me, of a truck pulling into a farm yard and turning round to make its getaway -- but the thief had covered the license plate and pulled a hat down over his face.

And CCTV certainly won't deter the committed terrorist, least of all a suicide bomber, who's not a bit worried about being caught after the fact, let alone about the possibility of facing earthly justice. Take a closer look at the pictures the British police released of the London bombers. It was at 21 minutes and 54 seconds past 7 a.m. on July 7 that camera 14 in Luton station captured murder in the making; before their successful suicide attacks, the four young bombers appear chillingly relaxed, nonchalant in the face of imminent death. In the July 21 shots, on the other hand, there are signs of confusion, perhaps even panic, in the expressions of the men whose plot so unexpectedly fizzled.

Those images have put faces -- and now names -- to men who attempted the unthinkable. But they can't solve the ultimate mystery. What on earth was going on inside those men's heads? Had they been brainwashed, as one of their families has suggested? We won't know the answer to those questions unless we come up with technology that can read people's minds.

Now that's really something to worry about.

Author's e-mail:

Frances Stead Sellers is an assistant editor of Outlook. She grew up in Britain and holds dual citizenship there and in the United States.

The eyes have it:

Suspects in the bombing attempts in London caught on CCTV.