Since Sept. 11, it has become much harder to get such information from the federal government, a growing number of states and public libraries as heightened concern about national security has often trumped the public's "right to know."

U.S. intelligence officials believe the Chinese military is working to launch wide-scale cyber-attacks on American and Taiwanese computer networks, including Internet-linked military systems considered vulnerable to sabotage, according to a classified CIA report.

U.S. Intelligence officials are concerned that a recent rise in electronic attacks against government and military computer networks in the United States may be the work of pro-Iraqi hackers and could signal a "potential crisis" in national security.

In a significant shift in policy, the Bush administration has ordered U.S. federal agencies to rely much more heavily on private satellite companies to provide images from space.