Gwinnett County library patrons may have their Web browser history recorded by library staff when someone complains about suspected child pornography on a library computer, under new rules taking effect Monday.

The policy change treads the line between privacy and concerns over protecting children, said library board member Brett Taylor. It's a reaction to a complaint last year from a patron who believed she saw adult pornography on another user's computer screen. The complaint drew the library into a public discussion of its Internet use policies.

"We've never had a complaint that somebody was viewing child pornography," Taylor said. "But with the pressure, we thought we would cover all the bases."

The new rule requires a senior library staff member to respond to a complaint by observing the screen of the complained-about computer user, said Rhonda Boyd, deputy director of the Gwinnett County Public Library. If, in the opinion of the staff member, the material is child pornography, then the library's technical staff will run a computer program to capture a record of Internet addresses visited during that computer user's session. Library staff will then forward the complaint to law enforcement officers after another review.

The board drew the line at child pornography because it is clearly illegal, Taylor said. With any other kind of content, librarians would find themselves in a constitutionally gray area, he said.

Georgia law prevents libraries from recording the reading history of its patrons. While Gwinnett County lawyers vetted the library's policy change, it may still be challenged, Taylor said.

"It's possible that the law that protects reading history doesn't protect Internet history," he said.

Most library computers in Gwinnett available to the public use a filtering program to block obscene Web sites. Because the filter cannot be allowed to block material which is not clearly obscene, it is not perfectly effective, Taylor said.

For example, "you can't just block YouTube," Taylor said. "If you do, you really are cutting off people's First Amendment rights."

Each of the 14 library branches in Gwinnett has at least one computer that doesn't have a filtering program, set off from other terminals, Taylor said.

"People have the right, even under the [federal child protection] laws, to get unfiltered Internet access in the library, if it's reasonable," Taylor said. "In our case, we're a fairly large library. If it looks like it could be harmful to minors, they're instructed to tell the person that they have certain rights to use a computer in another part of the library."

The brouhaha prompted the library to give patrons a questionnaire about children's use of the Internet at the library. The survey asked, among other questions, if library patrons had seen objectionable content on other people's computers. It also asked if the library should allow parents to restrict their children's Internet access privileges. Library patrons sign on to the Internet with their library cards, but a software change would allow the library to block certain cards from access, Taylor said.

"We were being asked to restrict children's rights on the Internet," he said. "It came down to asking Gwinnett's parents what they want."