While fear of another terrorist attack drove many new proposals, it wasn't the only motivator. Concerns about identity theft, medical privacy and the vulnerability of computerized records have sparked many pieces of legislation, too.

Lawmakers say they are recalibrating the balance between information that could be used against society and what society at large needs to know.

"Since Sept. 11, we're looking at information like plans for our nuclear plants, the records of our bridges and transportation systems. All of the critical information that is out there that we don't necessarily want to put in the hands of a terrorist," said New York state Sen. Nick Spano, a Republican who had proposed tightening legislation soon after the attacks.

"It's a very difficult balance between the public's right to know and the public's right to security," Spano said. A different security measure ultimately became law, limiting access to information about infrastructure from airports to cellular phone systems. Last year, Spano authored a law that strengthened public access by setting a strict deadline for state agencies to respond to requests for information.

The give and take of a legislature usually forces changes to such bills — like a measure proposed last year in Oklahoma, where freshman state Sen. Charles Wyrick, a Democrat, sought to completely exempt the state's new Department of Homeland Security from the Open Meetings Act and Open Records Act.

"I don't know why all of a sudden the holy grail of security and safety is now closing records," Mark Thomas, head of the Oklahoma Press Association, said after the bill was introduced. "It seems to me we would be more secure if we knew what was going on around us. . . . Apparently there are those in government who want to close all these records and say, 'We'll keep you safe, trust us.' "

Negotiations brought a compromise. The law that passed allowed the department to keep communications between the agency and the federal government confidential, along with security plans for private businesses.

"We had to fight that out, and basically it ended up being an equal distribution of unhappiness," Thomas said.

Still, the numerical data shows which side got more out of negotiations overall: The AP analysis of 1,023 new laws dealing with public access to government information found that more than 60 percent closed access. Just over a quarter created new avenues of access. The rest had a neutral effect, often through technical changes to existing laws.

Those laws emerged from just over 3,500 bills. Often, several legislators interested in a topic will each introduce a bill knowing that only one is likely to pass. In some states, the same legislation is introduced in both House and Senate chambers to speed action and build support.