Start a raucous debate in most local libraries and you'd surely expect the matron of the stacks to come over and give you a vicious shushing.

But after the Sept. 11 terrorist attacks, the role of the nation's public centers of knowledge is proving to be far from a closed book.

The issue was highlighted in the case of a Florida librarian who called the FBI with a tip.

On Sept. 15, Kathleen Hensman, a reference librarian with the Delray Beach Public Library, just north of Boca Raton, read an article in a local newspaper listing the names of the suspected hijackers. On that list, she found three names of men she believed had used the library computers over the summer.

"They didn't have library cards as far as I know, but for some reason their names stuck in the mind of the librarian," library director John Callahan said. "We're pretty sure they were in the library."

Among them, he said, was Marwan Al-Shehhi, 23, whom the U.S. government suspects of being the pilot of United Airlines Flight 175, which crashed into the south tower of the World Trade Center.

Hensman related her suspicions to Callahan, who contacted local police. The police in turn called the FBI, who got a subpoena, swooped down on the library and took away two of its computers for analysis.

Callahan said the library doesn't know what the three men had been using the computers for.

But while the computers remained intact, the library's reputation didn't. Erroneous news reports said that the library had reprimanded Hensman for violating the privacy of library patrons.

Hensman in fact worked through the library, Callahan said, and neither she nor the library violated the state of Florida's confidentiality regulations.

"Florida law ... says that you need a subpoena. The FBI got a subpoena in this case, so that was totally within the laws," he said. "And the law does not cover the recollection of a librarian."

But the story made national news, enraging people across the country who thought the library was bending over backwards for issues that seemed unimportant when the nation was under attack.

The American Library Association issued a public statement that reminded libraries to be mindful of their states' confidentiality rules.

"If librarians do not follow state confidentiality laws and legal procedures, they run the risk of actually hindering ongoing law enforcement investigations," the statement read. "States created confidentiality laws to protect the privacy and freedoms Americans hold dear."

ALA spokeswoman Larra Clark emphasized that the statement did not reprimand Hensman and that the organization was aware that the library had played by Florida's privacy rules.

"The ALA doesn't ever reprimand librarians. We're not an enforcement library," she said from the organization's Chicago headquarters. "We are made up of librarians, our policies are made by librarians and we work on behalf of librarians, so doing that would be like pointing the finger at ourselves."

Likely less supportive of Hensman was one of the ALA's 182 councilors, who proposed a resolution that would take a strong stand on the war on terror. Mark Rosenzweig's resolution would state that the ALA opposes the war in Afghanistan and have libraries post warnings to patrons that they may be under FBI surveillance. The ALA would also declare that it "opposed the conduct under any circumstances of 'homeland security' through abridgements of human rights" and would abide by conditions of legally protected confidentiality.

Rosenzweig did not immediately respond to an e-mail. Calls to his office number as listed by the ALA were answered by a woman who said he no longer worked there.

Clark said the resolution is only in the preliminary stages and may not even have been seconded for debate, but she said it didn't represent the ALA's attitude.

"It may well be debated by the larger body, but at this point it's one person's perspective," she said.