Howard County librarian Marjorie Lewis spots them often, a couple of regulars looking at naughty pictures on one of the 10 computers at the Central Library in Columbia that offer free access to the Internet.

The two are only a fraction of the thousands of people who stream through the library, Lewis said. No patron has ever complained about them or anyone else who uses the computers to look at salacious cyberspace photos. And like many librarians, Lewis sees no need to thwart any adult whose choice of the word "hot" as an Internet search term has nothing to do with climatology.

Others, however, would like to make such searches tougher.

With three-fourths of the nation's libraries offering free access to the Internet, bills are wending through Congress that would force them to filter out many of the Web sites that deal with adult material, if the libraries want federal subsidies.

"Libraries shouldn't use federal tax money to put pornography on their shelves, and they shouldn't put it on their desktops or laptops," Republican presidential aspirant Elizabeth Dole said recently.

But to many librarians in the region--and the nation--the proposals are a solution in search of a problem.

"It's been blown way out of proportion. That's what our librarians are telling us," said Joyce Kelly, a spokeswoman for the American Library Association.

A random sampling of area libraries turned up few specific instances of librarians encountering patrons looking at pornographic sites, at least in any way that bothered other library users.

"I know of somebody who uses a Montgomery County library who goes into pornographic sites. It's a single case out of thousands who use our libraries," said Leila Shapiro, who runs the Bethesda Regional Library. "Most adults aren't going to tap into this at public libraries, because they don't want people looking over their shoulders."

In Prince George's County, Micki Freeny, the associate director for branch services, said the library's policy allows librarians to ask patrons to exit Web sites that aren't "appropriate." But, she added, "it's never come up as an issue."

Many librarians said that filters might block Web sites that are not pornographic--on breast cancer, for example--depriving people of information they may need. And purveyors of sex sites find ways around filters, making them ineffective, the librarians said.

Beyond that, most bridle at the notion of limiting information.

"We believe it's an individual's choice as to what they view and not someone else's," Kelly said.

Lewis, the Howard County librarian, said some patrons "spend a long time looking" at X-rated sites. But, she added, "we don't say anything to them because it's their right to read anything they want. We don't hassle them unless there's somebody waiting for a computer."

The U.S. House of Representatives recently passed a measure--tacked onto a juvenile justice bill--that would require any school or library receiving federal subsidies for Internet connections to install filters to prevent access to Web sites offering obscene material. In addition, children would be denied access to any site the community deems harmful to minors, such as those dealing in weapons, according to Kim Linthicum, senior legislative assistant to Rep. Bob Franks (R-N.J.), the bill's chief sponsor.

"For generations, schools and libraries have routinely decided what books are appropriate for children to read," Franks said in a statement. "This amendment would merely require that these institutions exercise that same standard of care when it comes to the latest advances of the information age."

The bill is pending in the Senate, along with a similar bill sponsored by Sen. John McCain (R-Ariz.), who is a presidential candidate.

The current debate in Congress follows recent controversies in Loudoun and Anne Arundel counties.

In 1998, the Loudoun library system initiated one of the nation's most restrictive Internet filtering policies. But U.S. District Judge Leonie M. Brinkema, a former librarian, ruled that the filters violated free speech rights and did not serve a compelling government interest.

After Brinkema's decision, Loudoun's library board decided to allow adults to choose whether they want unfiltered access to the Internet.

Anne Arundel County, a leader among Maryland libraries in providing free access to the Internet, found itself embroiled in a similar dispute in 1997. A woman complained that she had seen nude people on a computer screen as she walked with her children through a branch library in Glen Burnie.

Library trustees voted against filters but began installing privacy screens on many computer monitors. The screens, which are flat and look much like shields used to cut glare, make it difficult for anyone other than the person sitting directly at the computer to see what's on the monitor, libraries spokeswoman Andrea Lewis said. The library also now requires that adults who want to view pornography must use a monitor with a privacy screen.

But, Lewis added, not many people seem to look at sex sites. She said there has not been much change since 1997, when statistics showed that of the thousands of World Wide Web sites accessed by Anne Arundel library patrons, only 0.03 percent were "mildly pornographic."

About 80 percent of the nation's libraries have developed "acceptable use" statements for patrons using the Internet. Anne Arundel's also includes a prohibition on minors using the Internet to view pornography and says librarians will stop youngsters who try.