Government officials say factual Northwest Airline passenger data were not used in a study to pinpoint potential terrorists and that public U.S. Census data were used separately.
The National Aeronautics and Space Administration (NASA) “replaced actual passenger attributes with fictitious attributes to make the data anonymous,” said David Morse, NASA Ames Research Center spokesman.
Northwest Airlines is under fire by privacy advocates who are demanding the Transportation Department investigate the company for sharing private passenger information.
Northwest gave NASA researchers 90 days of passenger flight information, but Mr. Morse said only information from one day was “deidentified” for use. According to the NASA study, 439,381 airline passenger examples were used.
The study also used the census’s Public Use Micro Data (PUMS), which contains 5 million households and 5 million personal records from 1990, to test whether a data-mining program could pinpoint anomalies. Mr. Morse said it was never cross-referenced with the airline passenger information.
“They were looking to see if they could find patterns in the data in a generic manner,” he said.
A Census Bureau spokesman said NASA did not ask for additional information and said the long-form census information provided in the data cannot be traced to individuals. The latest technology is employed to prevent “intrusive” research, said spokesman Mark Tolbert.
An ACLU spokesman said they were assured private information was not disclosed but asked for written confirmation and asked the census to disclose whether any federal agency since September 11 has requested personal information.
The microdata contain “population and household surveys” and “individuals’ responses that represent only samples of the population and have had all individual identifiers (such as name and address) removed from the records,” says the Census Bureau’s privacy statement.
“To protect confidentiality, the Census Bureau may modify distinguishing characteristics (such as high levels of income), and restrict geographic identifiers (such as the name of a city) so that populations are composed of at least 100,000 people. This is done to protect the identity of individuals,” the statement says.
The NASA study did not disclose findings from the passenger data-mining research but listed some examples of anomalies, such as a retired 19-year-old discovered in the census information.
“A 19 year old, White, female with Asian ancestry and Mexican Hispanic origin with a disability that limits but does not prevent work. She earned $123k in business income and $38k in retirement income (which may include payments for disabilities) and is also enrolled in school,” NASA listed as an anomaly.
The study said “as many as 70 percent of the persons (in the 1990 US census) were unique in terms of a combination of 42 simple personal and household characteristics.”
Bob Barr, former Georgia congressman and a leading civil libertarian wants the entire study and methods investigated by Congress and the government.
“NASA has a distinguished history of conducting work critically important to the future of humanity, and it is deeply disappointing to see that work being endangered by inept meddling in affairs clearly outside the agency’s jurisdiction,” Mr. Barr said.