The Internet revolution has changed the local library. Circulation is up, budgets are up and, with more high-tech resources, the role of librarian now includes thwarting sex acts on the premises. One of Adamson’s colleagues stumbled on three teenagers, apparently heated up by what they’d been watching on the computer, having group sex in the bathroom. Circulation supervisors in a library in Austin, Texas, witnessed an adult patron telling children how to access Internet porn. “They were being exposed to things they’d really rather not see,’’ says assistant library director Cynthia Kidd.

Librarians tend to support the First Amendment, so the idea of restricting Internet access doesn’t come easily. But with porn seekers continuing to increase, 15 percent of the nation’s 9,000 public-library systems (Austin’s included) now use filters. The software has flaws; the American Library Association says it arbitrarily suppresses access to otherwise harmless material.

Still, censorship debates become irrelevant when sites violate obscenity and child-pornography laws. In May a lawyer for Adamson and 11 of her colleagues filed a sex-discrimination claim against the library with the federal Equal Employment Opportunity Commission, charging that access to Internet sex sites created “an indisputably hostile, offensive and palpably unlawful working environment.’’ Pressure from anti-porn taxpayers finally led library director Mary Lawson to ban the viewing of “sexually offensive’’ material. Undercover cops now patrol the computer terminals.

Other cities have tried different remedies. After a convicted child molester’s 1999 arrest for distributing child porn from a computer at the L.A. Public Library, officials opted for no-sex search engines on some computers. Denver took similar action, says library director Linda Cumming. Beyond that, though, “the librarians need to understand it’s just a condition of the job today,’’ Cumming says. She tells her staff sympathetically, “I’m sure this isn’t what you expected when you went to library school.''