E-gov's 'electronic shadow'

The growing ability federal agencies have to collect, store, retrieve, compare and analyze electronic records offers both benefit and risk, the General Accounting Office reports.

By comparing data, agencies can better track program results, plan new initiatives and contribute to knowledge that might benefit millions. "Despite these benefits, concerns about personal privacy are relevant," GAO's April report cautioned.

Among the growing number of agencies and programs sharing data are:

* The Census Bureau, the IRS and the Social Security Administration.

* The IRS and the Department of Health and Human Services.

* The Substance Abuse and Mental Health Services Administration and various employment and law enforcement agencies.

* The Department of Labor and the Social Security Administration.

* The Centers for Disease Control and Medicare.

* The National Cancer Institute and the Health Care Financing Administration.

* The National Institute for Occupational Safety and Health and chemical plant operators.

* The National Institute on Aging, the Social Security Administration and various states.

Federal agencies have a long history of creating databases with "de-identified information," or data that has been stripped of information linked to specific individuals, such as names, birth dates, ZIP codes and the like.

But in recent years, there is rising concern that the increasing number of databases and growing sophistication of computers make it possible to link de-identified information with identified data, such as voter registration lists, and "re-identify" it.

When information is linked in this way, some believe it can potentially provide "an electronic shadow of a person" that is as identifying as a fingerprint, the GAO report said.