The Rand Corp. identified only four Web pages that might merit the restrictions imposed after the Sept. 11, 2001, attacks. It urged government officials to consider reopening public access to about three dozen Web pages that were withdrawn from the Internet in the name of homeland security.
"It's a good time to take a closer look at the choices that they made at the time," said John Baker, principal author of the study that was funded by the National Geospatial Intelligence Agency, the government's intelligence mapping agency.
Advocates of open government said the report shows that President Bush's administration acted rashly after the suicide attacks when it scrubbed numerous government Web sites.
"It was a gigantic mistake, and I hope the study brings some rationality back to this policy," said Steven Aftergood, director of the Federation of American Scientists' project on government secrecy. "Up to now, decisions have been made on a knee-jerk basis."
Rand's National Defense Research Institute identified 629 federal databases accessible from the Internet that contain critical data about specific locations and "appeared to be the most sensitive sites."
The study, conducted between mid-2002 and mid-2003, found no federal Web sites that contained target information essential to a terrorist — in other words, that without which an attack couldn't be launched.
It identified four databases — less than 1 percent — where restricting access probably would enhance security. None was available to the general public anymore. Those sites included two devoted to pipelines, one to nuclear reactors and one to dams.
Researchers recommended that officials evaluate 66 databases with some useful information, but they didn't anticipate restrictions would be needed because similar or better data probably could be easily obtained elsewhere.
The remaining 559 databases "are probably not significant for addressing attackers' information needs and do not warrant any type of public restriction," the report said. It said that any information they contain that could be useful to terrorists is easily obtained elsewhere, often by simple, legal observation in an open society.
The Rand researchers found that 30 federal agencies or departments make public what is known as geospatial information on paper or online about critical or symbolic locations and structures. That kind of data can be as simple as a telephone book or as complex as an Internet database that discloses how many people live near each of the nation's power plants or toxic chemical storage sites.
After Sept. 11, federal agencies scrambled to pull such data off the Internet. The Transportation Department removed pipeline maps. The Environmental Protection Agency deleted descriptions of risk management plans for chemicals stored at 15,000 sites. The Nuclear Regulatory Commission brought down its Web site, although much is now back online.
By Michael J. Sniffen