Doug Huffman
Banned
imported post
http://ap.google.com/article/ALeqM5gn73rNmeGnZBP2y4kjTylgaqHciwD913CMDG1
Study secretly tracks cell phone users outside US 4 hours ago
WASHINGTON (AP) — Researchers secretly tracked the locations of 100,000 people outside the United States through their cell phone use and concluded that most people rarely stray more than a few miles from home.
The first-of-its-kind study by Northeastern University raises privacy and ethical questions for its monitoring methods, which would be illegal in the United States.
It also yielded somewhat surprising results that reveal how little people move around in their daily lives. Nearly three-quarters of those studied mainly stayed within a 20-mile-wide circle for half a year.
The scientists would not disclose where the study was done, only describing the location as an industrialized nation.
Researchers used cell phone towers to track individuals' locations whenever they made or received phone calls and text messages over six months. In a second set of records, researchers took another 206 cell phones that had tracking devices in them and got records for their locations every two hours over a week's time period.
The study was based on cell phone records from a private company, whose name also was not disclosed.
Study co-author Cesar Hidalgo, a physics researcher at Northeastern, said he and his colleagues didn't know the individual phone numbers because they were disguised into "ugly" 26-digit-and-letter codes.
That type of nonconsensual tracking would be illegal in the United States, according to Rob Kenny, a spokesman for the Federal Communications Commission. Consensual tracking, however, is legal and even marketed as a special feature by some U.S. cell phone providers.
The study, published Thursday in the journal Nature, opens up the field of human-tracking for science and calls attention to what experts said is an emerging issue of locational privacy.
"This is a new step for science," said study co-author Albert-Lazlo Barabasi, director of Northeastern's Center for Complex Network Research. "For the first time we have a chance to really objectively follow certain aspects of human behavior."
Barabasi said he spent nearly half his time on the study worrying about privacy issues. Researchers didn't know which phone numbers were involved. They were not able to say precisely where people were, just which nearby cell phone tower was relaying the calls, which could be a matter of blocks or miles. They started with 6 million phone numbers and chose the 100,000 at random to provide "an extra layer" of anonymity for the research subjects, he said.
Barabasi said he did not check with any ethics panel. Had he done so, he might have gotten an earful, suggested bioethicist Arthur Caplan at the University of Pennsylvania.
"There is plenty going on here that sets off ethical alarm bells about privacy and trustworthiness," Caplan said.
Studies done on normal behavior at public places is "fair game for researchers" as long as no one can figure out identities, Caplan said in an e-mail.
"So if I fight at a soccer match or walk through 30th Street train station in Philly, I can be studied," Caplan wrote. "But my cell phone is not public. My cell phone is personal. Tracking it and thus its owner is an active intrusion into personal privacy."
Paul Stephens, policy director at the Privacy Rights Clearinghouse in San Diego, said the nonconsensual part of the study raises the Big Brother issue.
"It certainly is a major concern for people who basically don't like to be tracked and shouldn't be tracked without their knowledge," Stephens said.
Study co-author Hidalgo said there is a difference between being a statistic — such as how many people buy a certain brand of computer — and a specific example. The people tracked in the study are more statistics than examples.
"In the wrong hands the data could be misused," Hidalgo said. "But in scientists' hands you're trying to look at broad patterns.... We're not trying to do evil things. We're trying to make the world a little better."
Knowing people's travel patterns can help design better transportation systems and give doctors guidance in fighting the spread of contagious diseases, he said.
The results also tell us something new about ourselves, including that we tend to go to the same places repeatedly, he said.
"Despite the fact that we think of ourselves as spontaneous and unpredictable ... we do have our patterns we move along and for the vast majority of people it's a short distance," Barabasi said.
The study found that nearly half of the people in the study pretty much keep to a circle little more than six miles wide and that 83 percent of the people tracked mostly stay within a 37-mile wide circle.
But then there are the people who are the travel equivalent of the super-rich, said Hidalgo, who travels more than 150 miles every weekend to visit his girlfriend. Nearly 3 percent of the population regularly go beyond a 200-mile wide circle. Less than 1 percent of people travel often out of a 621-mile circle.
But most people like to stay much closer to home. Hidalgo said he understands why: "There's a lot of people who don't like hectic lives. Travel is such a hassle."
On the Net:
Researchers have come up with a new use for the ubiquitous mobile phone: tracking human movements. By monitoring the signals from 100,000 mobile-phone users sending and receiving calls and text messages, a team from Northeastern University in Boston, Massachusetts, has worked out some apparently universal laws of human motion.
The results could help epidemiologists to predict how viruses will spread through populations, and help urban planners and traffic forecasters to allocate resources.
Albert-László Barabási and his colleagues show that most people, perhaps unsurprisingly, are creatures of habit. They make regular trips to the same few destinations such as work and home, and pepper these with occasional longer forays such as vacations.
The distances people covered varied widely between individuals, but follow a similar pattern — most people move on average a short distance on a daily basis, whereas a few hardy souls move long distances in a short time. The results are reported in Nature [sup]1[/sup].
On track These patterns might sound obvious, but as data on individual human movements are difficult to come by, researchers haven't been able to study them precisely. “We don’t really know how humans move around,” says Barabási. “When you look at the population as a whole, there is no way of describing the patterns. The problem with answering this question is that people normally are not tracked — but today we are tracked thanks to the phones we carry with us.”
So Barabási and his colleagues teamed up with a mobile-phone company (unidentified to protect customers' privacy), who provided them with anonymized data on which transmitter towers had handled the calls and texts for 100,000 individuals over the course of 6 months.
The results fit with a 2006 attempt to track human movements using banknotes as a proxy measure, also published in Nature [sup]2[/sup]. Researchers led by Dirk Brockmann, now at Northwestern University in Illinois, analysed the movements of more than half a million US one-dollar bills as they were passed around over five years. The team found similar patterns of lots of short movements and occasional longer ones.
Mobile money But because banknotes are passed from person to person and rarely stay in the same pocket for long, that study could only derive an average picture of movement. Barabási's study “answers questions about individual variability that we were unable to address with the dollar bills”, Brockmann says.
Strict data-protection laws prevented Brockmann from carrying out his own version of the mobile-phone study in Germany, where he was based until recently. Mobile-phone data have the potential to reveal information about where individuals live and work. “I’ve been trying to get my hands on mobile-phone data but it isn't possible,” he says.
Because of privacy considerations, Barabási’s report does not divulge where in the world the data are from – location could conceivably affect the patterns a great deal in light of people's differing daily habits in different countries.
“It’s weird to see such mathematical regularities in such complex behaviours,” says Brockmann. The challenge now is to find out why something as complex as human movement follows such consistent patterns, he says. “Neither study can answer that question.”
http://ap.google.com/article/ALeqM5gn73rNmeGnZBP2y4kjTylgaqHciwD913CMDG1
Study secretly tracks cell phone users outside US 4 hours ago
WASHINGTON (AP) — Researchers secretly tracked the locations of 100,000 people outside the United States through their cell phone use and concluded that most people rarely stray more than a few miles from home.
The first-of-its-kind study by Northeastern University raises privacy and ethical questions for its monitoring methods, which would be illegal in the United States.
It also yielded somewhat surprising results that reveal how little people move around in their daily lives. Nearly three-quarters of those studied mainly stayed within a 20-mile-wide circle for half a year.
The scientists would not disclose where the study was done, only describing the location as an industrialized nation.
Researchers used cell phone towers to track individuals' locations whenever they made or received phone calls and text messages over six months. In a second set of records, researchers took another 206 cell phones that had tracking devices in them and got records for their locations every two hours over a week's time period.
The study was based on cell phone records from a private company, whose name also was not disclosed.
Study co-author Cesar Hidalgo, a physics researcher at Northeastern, said he and his colleagues didn't know the individual phone numbers because they were disguised into "ugly" 26-digit-and-letter codes.
That type of nonconsensual tracking would be illegal in the United States, according to Rob Kenny, a spokesman for the Federal Communications Commission. Consensual tracking, however, is legal and even marketed as a special feature by some U.S. cell phone providers.
The study, published Thursday in the journal Nature, opens up the field of human-tracking for science and calls attention to what experts said is an emerging issue of locational privacy.
"This is a new step for science," said study co-author Albert-Lazlo Barabasi, director of Northeastern's Center for Complex Network Research. "For the first time we have a chance to really objectively follow certain aspects of human behavior."
Barabasi said he spent nearly half his time on the study worrying about privacy issues. Researchers didn't know which phone numbers were involved. They were not able to say precisely where people were, just which nearby cell phone tower was relaying the calls, which could be a matter of blocks or miles. They started with 6 million phone numbers and chose the 100,000 at random to provide "an extra layer" of anonymity for the research subjects, he said.
Barabasi said he did not check with any ethics panel. Had he done so, he might have gotten an earful, suggested bioethicist Arthur Caplan at the University of Pennsylvania.
"There is plenty going on here that sets off ethical alarm bells about privacy and trustworthiness," Caplan said.
Studies done on normal behavior at public places is "fair game for researchers" as long as no one can figure out identities, Caplan said in an e-mail.
"So if I fight at a soccer match or walk through 30th Street train station in Philly, I can be studied," Caplan wrote. "But my cell phone is not public. My cell phone is personal. Tracking it and thus its owner is an active intrusion into personal privacy."
Paul Stephens, policy director at the Privacy Rights Clearinghouse in San Diego, said the nonconsensual part of the study raises the Big Brother issue.
"It certainly is a major concern for people who basically don't like to be tracked and shouldn't be tracked without their knowledge," Stephens said.
Study co-author Hidalgo said there is a difference between being a statistic — such as how many people buy a certain brand of computer — and a specific example. The people tracked in the study are more statistics than examples.
"In the wrong hands the data could be misused," Hidalgo said. "But in scientists' hands you're trying to look at broad patterns.... We're not trying to do evil things. We're trying to make the world a little better."
Knowing people's travel patterns can help design better transportation systems and give doctors guidance in fighting the spread of contagious diseases, he said.
The results also tell us something new about ourselves, including that we tend to go to the same places repeatedly, he said.
"Despite the fact that we think of ourselves as spontaneous and unpredictable ... we do have our patterns we move along and for the vast majority of people it's a short distance," Barabasi said.
The study found that nearly half of the people in the study pretty much keep to a circle little more than six miles wide and that 83 percent of the people tracked mostly stay within a 37-mile wide circle.
But then there are the people who are the travel equivalent of the super-rich, said Hidalgo, who travels more than 150 miles every weekend to visit his girlfriend. Nearly 3 percent of the population regularly go beyond a 200-mile wide circle. Less than 1 percent of people travel often out of a 621-mile circle.
But most people like to stay much closer to home. Hidalgo said he understands why: "There's a lot of people who don't like hectic lives. Travel is such a hassle."
On the Net:
- Nature: http://www.nature.com/nature
Researchers have come up with a new use for the ubiquitous mobile phone: tracking human movements. By monitoring the signals from 100,000 mobile-phone users sending and receiving calls and text messages, a team from Northeastern University in Boston, Massachusetts, has worked out some apparently universal laws of human motion.
The results could help epidemiologists to predict how viruses will spread through populations, and help urban planners and traffic forecasters to allocate resources.
Albert-László Barabási and his colleagues show that most people, perhaps unsurprisingly, are creatures of habit. They make regular trips to the same few destinations such as work and home, and pepper these with occasional longer forays such as vacations.
The distances people covered varied widely between individuals, but follow a similar pattern — most people move on average a short distance on a daily basis, whereas a few hardy souls move long distances in a short time. The results are reported in Nature [sup]1[/sup].
On track These patterns might sound obvious, but as data on individual human movements are difficult to come by, researchers haven't been able to study them precisely. “We don’t really know how humans move around,” says Barabási. “When you look at the population as a whole, there is no way of describing the patterns. The problem with answering this question is that people normally are not tracked — but today we are tracked thanks to the phones we carry with us.”
So Barabási and his colleagues teamed up with a mobile-phone company (unidentified to protect customers' privacy), who provided them with anonymized data on which transmitter towers had handled the calls and texts for 100,000 individuals over the course of 6 months.
The results fit with a 2006 attempt to track human movements using banknotes as a proxy measure, also published in Nature [sup]2[/sup]. Researchers led by Dirk Brockmann, now at Northwestern University in Illinois, analysed the movements of more than half a million US one-dollar bills as they were passed around over five years. The team found similar patterns of lots of short movements and occasional longer ones.
Mobile money But because banknotes are passed from person to person and rarely stay in the same pocket for long, that study could only derive an average picture of movement. Barabási's study “answers questions about individual variability that we were unable to address with the dollar bills”, Brockmann says.
Strict data-protection laws prevented Brockmann from carrying out his own version of the mobile-phone study in Germany, where he was based until recently. Mobile-phone data have the potential to reveal information about where individuals live and work. “I’ve been trying to get my hands on mobile-phone data but it isn't possible,” he says.
Because of privacy considerations, Barabási’s report does not divulge where in the world the data are from – location could conceivably affect the patterns a great deal in light of people's differing daily habits in different countries.
“It’s weird to see such mathematical regularities in such complex behaviours,” says Brockmann. The challenge now is to find out why something as complex as human movement follows such consistent patterns, he says. “Neither study can answer that question.”
- References González, M. C. , Hidalgo, C. A. & Barabási, A.-L. Nature 453, 779–782 (2008).
- Brockmann, D. D. , Hufnagel, L. & Geisel, T. Nature 439, 462–465 (2006).
