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Page 13 of 21

$20M Cameras at New York's Freedom Tower are Pretty Sophisticated

If you have ever wondered how security guards can possibly keep an unfailingly vigilant watch on every single one of dozens of television monitors, each depicting a different scene, the answer seems to be (as you suspected): they can’t.

Instead, they can now rely on computers to constantly analyze the patterns, sizes, speeds, angles and motion picked up by the camera and determine—based on how they have been programmed—whether this constitutes a possible threat. In which case, the computer alerts the security guard whose own eyes may have been momentarily diverted. Or shut.

An alarm can be raised, for instance, if the computer discerns a vehicle that has been standing still for too long (say, a van in the drop-off lane of an airport terminal) or a person who is loitering while everyone else is in motion. By the same token, it will spot the individual who is moving rapidly while everyone else is shuffling along. It can spot a package that has been left behind and identify which figure in the crowd abandoned it. Or pinpoint the individual who is moving the wrong way down a one-way corridor.

Because one person’s “abnormal situation” is another person’s “hot dog vendor attracting a small crowd,” the computers can be programmed to discern between times of the day and days of the week.

Certainly interesting.

Posted on September 25, 2008 at 6:32 AM • View Comments

Gait Analysis from Satellite

Ignoring the sensationalist headline, this is interesting:

By analysing the movements of human shadows in aerial and satellite footage, JPL engineer Adrian Stoica says it should be possible to identify people from the way they walk—a technique called gait analysis, whose power lies in the fact that a person’s walking style is very hard to disguise.

Video taken from above shows only people’s heads and shoulders, which makes measuring the characteristic length and rhythm of a person’s stride impossible. That’s not true of shadows, though, Stoica told a security conference in Edinburgh, UK, last month. Shadows, he says, provide enough gait data to deduce a positive ID. To prove it, he has written software that recognises human movement in aerial and satellite video footage. It isolates moving shadows and uses data on the time of day and the camera angle to correct shadows if they are elongated or foreshortened. Regular gait analysis is then applied to identify people. In tests on footage shot from the sixth floor of a building, Stoica says his software was indeed able to extract useful gait data.

The article goes on to say that using satellite images would be harder, but that the basic idea is the same.

Of course, this is less useful for finding individuals and more useful for tracking a population as it moves about its day. But some individuals will have more distinctive gaits than others, and will be easier to track. Soon we may all need to walk with rocks in our shoes.

Posted on September 9, 2008 at 12:22 PM • View Comments

Doctoring Photographs without Photoshop

It’s all about the captions:

…doctored photographs are the least of our worries. If you want to trick someone with a photograph, there are lots of easy ways to do it. You don’t need Photoshop. You don’t need sophisticated digital photo-manipulation. You don’t need a computer. All you need to do is change the caption.

The photographs presented by Colin Powell at the United Nations in 2003 provide several examples. Photographs that were used to justify a war. And yet, the actual photographs are low-res, muddy aerial surveillance photographs of buildings and vehicles on the ground in Iraq. I’m not an aerial intelligence expert. I could be looking at anything. It is the labels, the captions, and the surrounding text that turn the images from one thing into another. Photographs presented by Colin Powell at the United Nations in 2003.

Powell was arguing that the Iraqis were doing something wrong, knew they were doing something wrong, and were trying to cover their tracks. Later, it was revealed that the captions were wrong. There was no evidence of chemical weapons and no evidence of concealment. Morris’s mockery of the sweeping interpretations made in Powell’s photographs.

There is a larger point. I don’t know what these buildings were really used for. I don’t know whether they were used for chemical weapons at one time, and then transformed into something relatively innocuous, in order to hide the reality of what was going on from weapons inspectors. But I do know that the yellow captions influence how we see the pictures. “Chemical Munitions Bunker” is different from “Empty Warehouse” which is different from “International House of Pancakes.” The image remains the same but we see it differently.

Change the yellow labels, change the caption and you change the meaning of the photographs. You don’t need Photoshop. That’s the disturbing part. Captions do the heavy lifting as far as deception is concerned. The pictures merely provide the window-dressing. The unending series of errors engendered by falsely captioned photographs are rarely remarked on.

Posted on August 27, 2008 at 7:27 AM • View Comments

Red Light Cameras Don't Work

Interesting: the solution to one problem causes another.

“The rigorous studies clearly show red-light cameras don’t work,” said lead author Barbara Langland-Orban, professor and chair of health policy and management at the USF College of Public Health. “Instead, they increase crashes and injuries as drivers attempt to abruptly stop at camera intersections.”

Comprehensive studies from North Carolina, Virginia, and Ontario have all reported cameras are associated with increases in crashes. The study by the Virginia Transportation Research Council also found that cameras were linked to increased crash costs. The only studies that conclude cameras reduced crashes or injuries contained “major research design flaws,” such as incomplete data or inadequate analyses, and were always conducted by researchers with links to the Insurance Institute for Highway Safety. The IIHS, funded by automobile insurance companies, is the leading advocate for red-light cameras since insurance companies can profit from red-light cameras by way of higher premiums due to increased crashes and citations.

And, of course, the agenda of the government is to increase revenue due to fines:

A 2001 paper by the Office of the Majority Leader of the U.S. House of Representatives reported that red-light cameras are “a hidden tax levied on motorists.” The report came to the same conclusions that all of the other valid studies have, that red-light cameras are associated with increased crashes and that the timings at yellow lights are often set too short to increase tickets for red-light running. That’s right, the state actually tampers with the yellow light settings to make them shorter, and more likely to turn red as you’re driving through them.

In fact, six U.S. cities have been found guilty of shortening the yellow light cycles below what is allowed by law on intersections equipped with cameras meant to catch red-light runners. Those local governments have completely ignored the safety benefit of increasing the yellow light time and decided to install red-light cameras, shorten the yellow light duration, and collect the profits instead.

The cities in question include Union City, CA, Dallas and Lubbock, TX, Nashville and Chattanooga, TN, and Springfield, MO, according to Motorists.org, which collected information from reports from around the country.

Posted on August 25, 2008 at 12:19 PM • View Comments

Speed Cameras Record Every Car

In this article about British speed cameras, and a trick to avoid them that does not work, is this sentence:

As vehicles pass between the entry and exit camera points their number plates are digitally recorded, whether speeding or not.

Without knowing more, I can guarantee that those records are kept forever.

EDITED TO ADD (7/25): As pointed out by Pete Darby in comments: Passenger moons speeding camera and gets his picture published even though the car was not speeding.

Police may take action against the man for public order offences and not wearing a seat belt.

Officers have the registration of the car, which was not breaking the speed limit, and intend to contact its owner.

It is understood the driver will not face prosecution as no driving offence was being committed.

How did they even know to look at the picture in the first place?

Posted on July 23, 2008 at 5:32 AM • View Comments

Exploiting the War on Photography

Petty thieves are exploiting the war on photography in Genoa:

As they were walking around, Jeff saw some interesting looking produce and pulled out his Canon G-9 Point-and-Shoot and took a few pictures. Within a few minutes a man came up dressed in plain clothes, flashed a badge, and told him he couldn’t take photos in the store. My brother said “no problem” (after all, it’s a private store, right?), but then the guy demanded my brother’s memory card.

My brother gave him that “Are you outta your mind” look and said, “No way!” Can you guess what happened next? The guy simply shrugged his shoulders and walked away.

My brother saw him in the store a little later, and the guy had a bag and was shopping. My brother made eye contact with him, and the guy turned away as though he didn’t want Jeff looking at him. Jeff feels like this wasn’t “official store security,” but instead some guy collecting (and then reselling) memory cards from unsuspecting tourists (many of whom might have just surrendered that card immediately).

Posted on July 10, 2008 at 6:54 AM • View Comments

Sunglasses that Hide your Face from Cameras

Clever. Article and video:

They work by mounting two small infrared lights on the front. The wearer is completely inconspicuous to the human eye, but cameras only see a big white blur where your face should be.

Building them is a snap: just take a pair of sunglasses, attach two small but powerful IR LEDS to two pairs of wires, one wire per LED. Then attach the LEDs to the glasses; the video suggests making a hole in the rim of the glasses to embed the LEDs. Glue or otherwise affix the wires to the temples of the glasses. At the end of the temples, attach lithium batteries. They should make contact with the black wire, but the red wires should be left suspended near the batteries without making contact. When you put them on the red wire makes contact, turning the lights on. It’s functional, but we’re thinking that installing an on/off switch would be more elegant and it would allow you to wear them without depleting the batteries.

EDITED TO ADD (7/8): Doubts have been raised about whether this works as advertised against paparazzi cameras. I can’t tell for sure one way or the other.

Posted on July 7, 2008 at 1:54 PM • View Comments

Random Stupidity in the Name of Terrorism

An air traveler in Canada is first told by an airline employee that it is “illegal” to say certain words, and then that if she raised a fuss she would be falsely accused:

When we boarded a little later, I asked for the ninny’s name. He refused and hissed, “If you make a scene, I’ll call the pilot and you won’t be flying tonight.”

More on the British war on photographers.

A British man is forced to give up his hobby of photographing buses due to harrassment.

The credit controller, from Gloucester, says he now suffers “appalling” abuse from the authorities and public who doubt his motives.

The bus-spotter, officially known as an omnibologist, said: “Since the 9/11 attacks there has been a crackdown.

“The past two years have absolutely been the worst. I have had the most appalling abuse from the public, drivers and police over-exercising their authority.

Mr McCaffery, who is married, added: “We just want to enjoy our hobby without harassment.

“I can deal with the fact someone might think I’m a terrorist, but when they start saying you’re a paedophile it really hurts.”

Is everything illegal and damaging now terrorism?

Israeli authorities are investigating why a Palestinian resident of Jerusalem rammed his bulldozer into several cars and buses Wednesday, killing three people before Israeli police shot him dead.

Israeli authorities are labeling it a terrorist attack, although they say there is no clear motive and the man—a construction worker—acted alone. It is not known if he had links to any terrorist organization.

New Jersey public school locked down after someone saw a ninja:

Turns out the ninja was actually a camp counselor dressed in black karate garb and carrying a plastic sword.

Police tell the Asbury Park Press the man was late to a costume-themed day at a nearby middle school.

And finally, not terrorism-related but a fine newspaper headline: “Giraffe helps camels, zebras escape from circus“:

Amsterdam police say 15 camels, two zebras and an undetermined number of llamas and potbellied swine briefly escaped from a traveling Dutch circus after a giraffe kicked a hole in their cage.

Are llamas really that hard to count?

EDITED TO ADD (7/2): Errors fixed.

Posted on July 3, 2008 at 12:57 PM • View Comments

CCTV Cameras

Pervasive security cameras don’t substantially reduce crime. There are exceptions, of course, and that’s what gets the press. Most famously, CCTV cameras helped catch James Bulger’s murderers in 1993. And earlier this year, they helped convict Steve Wright of murdering five women in the Ipswich area. But these are the well-publicised exceptions. Overall, CCTV cameras aren’t very effective.

This fact has been demonstrated again and again: by a comprehensive study for the Home Office in 2005, by several studies in the US, and again with new data announced last month by New Scotland Yard. They actually solve very few crimes, and their deterrent effect is minimal.

Conventional wisdom predicts the opposite. But if that were true, then camera-happy London, with something like 500,000, would be the safest city on the planet. It isn’t, of course, because of technological limitations of cameras, organisational limitations of police and the adaptive abilities of criminals.

To some, it’s comforting to imagine vigilant police monitoring every camera, but the truth is very different. Most CCTV footage is never looked at until well after a crime is committed. When it is examined, it’s very common for the viewers not to identify suspects. Lighting is bad and images are grainy, and criminals tend not to stare helpfully at the lens. Cameras break far too often. The best camera systems can still be thwarted by sunglasses or hats. Even when they afford quick identification—think of the 2005 London transport bombers and the 9/11 terrorists—police are often able to identify suspects without the cameras. Cameras afford a false sense of security, encouraging laziness when we need police to be vigilant.

The solution isn’t for police to watch the cameras. Unlike an officer walking the street, cameras only look in particular directions at particular locations. Criminals know this, and can easily adapt by moving their crimes to someplace not watched by a camera—and there will always be such places. Additionally, while a police officer on the street can respond to a crime in progress, the same officer in front of a CCTV screen can only dispatch another officer to arrive much later. By their very nature, cameras result in underused and misallocated police resources.

Cameras aren’t completely ineffective, of course. In certain circumstances, they’re effective in reducing crime in enclosed areas with minimal foot traffic. Combined with adequate lighting, they substantially reduce both personal attacks and auto-related crime in car parks. And from some perspectives, simply moving crime around is good enough. If a local Tesco installs cameras in its store, and a robber targets the store next door as a result, that’s money well spent by Tesco. But it doesn’t reduce the overall crime rate, so is a waste of money to the township.

But the question really isn’t whether cameras reduce crime; the question is whether they’re worth it. And given their cost (£500 m in the past 10 years), their limited effectiveness, the potential for abuse (spying on naked women in their own homes, sharing nude images, selling best-of videos, and even spying on national politicians) and their Orwellian effects on privacy and civil liberties, most of the time they’re not. The funds spent on CCTV cameras would be far better spent on hiring experienced police officers.

We live in a unique time in our society: the cameras are everywhere, and we can still see them. Ten years ago, cameras were much rarer than they are today. And in 10 years, they’ll be so small you won’t even notice them. Already, companies like L-1 Security Solutions are developing police-state CCTV surveillance technologies like facial recognition for China, technology that will find their way into countries like the UK. The time to address appropriate limits on this technology is before the cameras fade from notice.

This essay was previously published in The Guardian.

EDITED TO ADD (7/3): A rebuttal.

EDITED TO ADD (7/6): More commentary.

EDITED TO ADD (7/9): Another good survey article, and commentary.

Posted on June 26, 2008 at 1:18 PM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.