Business

‘Anonymized’ Credit Card Data Not So Anonymous, Study Shows

Published

11 years ago

January 30, 2015

In this May 9, 2012 file photo, a Visa credit card is offered at a store in New York’s Times Square. Credit card data isnt quite as anonymous as promised, a new study says. Scientists showed they can identify you with more than 90 percent accuracy by looking at just four purchases, three if the price is included and this is after companies wiped away personal details of credit card transactions. (AP Photo/Richard Drew, File)

SETH BORENSTEIN, Associated Press
JACK GILLUM, Associated Press

WASHINGTON (AP) — Credit card data isn’t quite as anonymous as promised, a new study says.

Scientists showed they can identify you with more than 90 percent accuracy by looking at just four purchases, three if the price is included — and this is after companies “anonymized” the transaction records, saying they wiped away names and other personal details. The study out of the Massachusetts Institute of Technology, published Thursday in the journal Science, examined three months of credit card records for 1.1 million people.

“We are showing that the privacy we are told that we have isn’t real,” study co-author Alex “Sandy” Pentland of MIT said in an email. His research found that adding just a glimmer of information about a person from an outside source was enough to identify him or her in the trove of financial transactions they studied.

Companies routinely strip away personal identifiers from credit card data when they share information with outsiders, saying the data is now safe because it is “anonymized.” But the MIT researchers showed that anonymized isn’t quite the same as anonymous.

Drawing upon a sea of data in an unnamed developed country, the researchers pieced together available information to see how easily they could identify somebody. They looked at information from 10,000 shops, with each data piece time-stamped to calculate how many pieces of data it would take on average to find somebody, said study lead author Yves-Alexandre de Montjoye, also of MIT.

In this case the experts needed only four pieces, three if price is involved.

As an example, the researchers wrote about looking at data from September 23 and 24 and who went to a bakery one day and a restaurant the other. Searching through the data set, they found there could be only person who fits the bill — they called him Scott. The study said, “and we now know all of his other transactions, such as the fact that he went shopping for shoes and groceries on 23 September, and how much he spent.”

It’s easier to identify women, but the research couldn’t explain why, de Montjoye said.

The study shows that when we think we have privacy when our data is collected, it’s really just an “illusion,” said Eugene Spafford, director of Purdue University’s Center for Education and Research in Information Assurance and Security. Spafford, who wasn’t part of the study, said it makes “one wonder what our expectation of privacy should be anymore.”

“It is not surprising to those of us who spend our time doing privacy research,” said outside expert Lorrie Faith Cranor, director of the CyLab Usable Privacy and Security Laboratory at Carnegie Mellon University. “But I expect it would be surprising to most people, including companies who may be routinely releasing de-identified transaction data, thinking it is safe to do so.”

Credit card companies and industry officials either declined comment or did not respond to requests for comment.

The once-obscure concept of metadata — or basic transactional information — grew mainstream in recent years following revelations by former National Security Agency contractor Edward Snowden. Those disclosures from once-top secret U.S. government documents revealed that the NSA was collecting the records of digital communications from millions of Americans not suspected of a crime.

The use of so-called “big data” has been a lucrative prospect for private companies aiming to cash in on the trove of personal information about their consumers. Retail purchases, online web browsing activity and a host of other digital breadcrumbs can provide firms with a wealth of data about you — which is then used in sophisticated advertising and marketing campaigns. And big data-mining was used extensively in the 2012 president election to win over voters or seek out prospective donors.

“While government surveillance has been getting a lot of press, and certainly the revelations warrant such scrutiny, a large number of corporations have been quietly expanding their use of data,” said privacy consultant and author Rebecca Herold. Studies like this show “how metadata can be used to pinpoint specific individuals. This also raises the question of how such data would be used within insurance actuarial calculations, insurance claims and adjustments, loan and mortgage application considerations, divorce proceedings.”

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Online:

Journal Science: http://www.sciencemag.org

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Seth Borenstein can be followed at http://twitter.com/borenbears

Jack Gillum can be followed at https://twitter.com/jackgillum

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Arts and Culture

IN MEMORIAM: Oakland Dance Legend Reginald Ray-Savage, 67

Savage lived his life as tribute to the teachers who had shared their wisdom on art and life with him. With a palpably genuine enthusiasm and desire to bring out the best in people, and pass the torch to the next generation, he poured into his students, as his teachers and mentors had into him. His infectious energy, love of life, and generosity of spirit inspired countless souls, both inside and outside the dance studio.

Published

2 hours ago

June 24, 2026

Oakland Post

Reginald Ray-Savage brought the old-school teaching techniques he learned in the Katherine Dunham Dance Company to the youth at the Oakland School for the Arts in 2003. Courtesy photo.

Special to The Post

Reginald Ray-Savage – dancer, choreographer, and beloved teacher, mentor, and inspiration to many – passed away on May 17. The Oakland School for the Arts dance instructor was 67.

Born Reginald Ray, Jr. in St. Louis, Missouri, on Sept. 5, 1958, he formally adopted the name ‘Savage,’ to honor the great Archie Savage, his mentor at Katherine Dunham’s Performing Arts Training Center where his dance training journey began in East St. Louis, Illinois.

He soon started dancing professionally with Katherine Dunham Dance Company, making dance a way of life. His grit, tenacity, and notorious work ethic brought him scholarships to train at multiple prestigious dance institutions, including The Ailey School (NYC) and Ruth Page School of Dance (Chicago), under the direction of acclaimed ballet instructor Larry Long and Dolores Lipinski-Long.

He danced with several companies including Joel Hall Dance Company, Ruth Page Ballet Chicago, Lyric Opera, Chicago City Ballet, American Festival Ballet, and touring productions of “Music Man” and “A Chorus Line”.

In 1989, Savage moved to Oakland where he started teaching seven days a week, amassing a devoted following that was attracted to his no-nonsense, impassioned, and effective old-school teaching style.

In 1992, at the insistence of his committed core of students, he founded Savage Jazz Dance Company (SJDC). Over a span of 30 years, Savage produced more than 100 original works, and tour SJDC nationally and internationally, performing at Casa del Jazz in Rome to a packed house and rave reviews—the first dance company to receive such an invitation.

Savage built SJDC into one of the Bay Area’s most respected dance companies, creating a signature style known for its combination of disciplined training, blended with rich artistic musical expression, and raw energy.

In 2003, Savage joined the Oakland School for the Arts as chair of the School of Dance. Over the next two decades, he created, built, and maintained a strong dance program, recognized, and respected by other dance institutions for forging well-trained and resilient dancers and human beings.

The depth of Savage’s tough love and care, and the skill of his teaching and mentoring are reflected in the careers of his students who have gone on to dance with the San Francisco Ballet, Martha Graham Dance Company, Mark Morris Dance Group, Janet Jackson, Ariana Grande, and companies across the globe.

Mark Kitaoka, a photographer hired by Savage in 2016, posted a living eulogy on the dance instructor.

“When I see the self-pride he builds in his students I am constantly impressed that people like Savage still exist in our ‘meme’ society,” Kitaoka wrote. “The kids he mentors are fiercely loyal to one another and I’m certain his methods teach each of those kids to put aside social status, race and gender and is replaced by solid loyalty for other souls.

“What Savage contributes to our world cannot be completely summed up in a few meager paragraphs but can be seen in the countless lives of those he has touched. Because of him, our world, and the world of the future is both a richer and better place.

Reginald Ray-Savage will forever be missed, remembered, and lovingly quoted. He is survived by his beloved wife, Alison Hurley, his sister, Sonia, and his brothers, Pierre, and Andre. May his inextinguishable spirit and impact live on in all the lives he touched.

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Activism

NCBW-OBAC Champions Black Women Entrepreneurs at Business en Blaque Expo

Aspiring entrepreneurs, small business owners, and financial professionals gathered for a day of education, networking, and community engagement. Participants attended workshops and panel discussions covering Business Literacy 101, wealth-building strategies, and entrepreneurship fundamentals.

Published

2 hours ago

June 24, 2026

Oakland Post

NCBW OBAC President Shari Wooldridge, moderator Jennifer Hammock, Eva Allen of Full Belly Bakery, Samantha Wise of Tip Top Shape, Ashley Harvey of Phoenix AI, Michelle McQueen, owner of Town Fare and Lucy Blue, at the "Business en Blaque” Entrepreneurship Workshop and Small Business Expo at Oakland's Executive Inn & Suites. Photo by Carla Thomas.

By Carla Thomas

The National Coalition of 100 Black Women, Inc., Oakland Bay Area Chapter (NCBW-OBAC) strengthened its commitment to economic empowerment through its 2026 Sisternomics initiative, offering free financial literacy and entrepreneurship resources aimed at advancing financial independence among Black women.

As part of the initiative, the “Business en Blaque” Entrepreneurship Workshop and Small Business Expo was held Saturday, May 23, at the Executive Inn & Suites in Oakland.

Aligned with the national theme “Resilient. Resourceful. Ready.,” the event highlighted NCBW-OBAC’s ongoing efforts to close economic gaps and expand opportunities for Black women.

One featured session, moderated by Jennifer Hammock, included panelists Eva Allen of Full Belly Bakery, Samantha Wise of Tip Top Shape, Ashley Harvey of Phoenix AI, and Michelle McQueen, owner of Town Fare and Lucy Blue. Panelists shared candid insights on their business journeys, including both successes and challenges.

McQueen and Blue emphasized the importance of maintaining clear financial records. “It’s important to know where you stand financially so you can make adjustments when necessary,” she said.

Ashley Harvey of Phoenix AI encouraged entrepreneurs to leverage AI tools such as ChatGPT and Claude to streamline operations and save time. She also stressed the importance of consistency in marketing. “Just put it out there. We’ve got to get over ourselves,” she said, noting that pre-scheduling social media posts can improve efficiency.

Wise echoed that sentiment, highlighting the value of consistent engagement. “I post two to three times a day because people want to be engaged, and your post doesn’t have to be perfect,” she said. She also shared that her faith continues to guide her work and purpose.

Allen spoke to the role of passion and community in entrepreneurship. “Baking is my passion, and it’s great to build community,” she said.

In addition to educational sessions, the Small Business Expo showcased local Black-owned businesses, creating a platform for visibility and support. The event fostered meaningful connections among attendees, speakers, and vendors.

Anita Russell of Working Solutions provided guidance on accessing capital, encouraging entrepreneurs to be prepared and intentional. “Do your homework, know your ‘why,’ and do not marginalize each other,” she said.