TOWSON, Md. -- An irate mother in Maryland claims that her teenage daughter was exposed to Internet pornography at a Baltimore County library, Baltimore television station WBAL reported.

The station said it may look like the person sitting next to you at a public library computer is doing legitimate research, but a closer look may show you a different story.

The station reported that when Willa Taylor's 17-year-old daughter went to the Northpoint library to do some research, she was shocked at what she caught a glimpse of on the computer next to her.

"She said while she was there, there was a man sitting right next to her and watching porn," Taylor said. "She saw the man's ... you know ... and the other picture was a woman's legs straight up in the air."

Her daughter was too embarrassed to speak with the station, but Taylor was irate and called the library.

"If I would have walked up there myself and I would have seen this next to my daughter, I would have choked the man like a chicken and then I would have been the one getting in trouble because this man is showing my daughter nudity," Taylor said.

Four years ago, WBAL's hidden camera caught people in several areas openly viewing pornography on library computers. Since then, Congress passed the Children's Internet Protection Act, which requires libraries install filters to receive federal funding.

A reporter took Taylor's concerns to Baltimore County's public library director, Jim Fish.

"That's very traumatic," Fish said. "I feel sorry. As a father of two teens, I have a great deal of empathy."

Fish said the library has had filters in place for seven years -- even before the Children's Internet Protection Act. He said that although they are getting better, they are not 100 percent effective.

The programs are designed to filter out material that could be offensive, but they can also end up filtering out legitimate sites about subjects like breast cancer or AIDS. If a patron has a valid reason for accessing those sites, a librarian can help bypass the filter.

"What we are trying to do is balance your intellectual freedom and your right to privacy as an individual while making sure people are not doing illegal things and maintaining a reasonable environment for folks and safe environment for children," Fish said.

The Family Research Council lobbied to have filters put in libraries and said they are helping, but they're not enough.

"You have to be vigilant with the filter -- can't just depend on the filter to do all the work," Charmaine Yoest of the Family Research Council said. "Make sure it's current as possible, check the level the filter is set on."

Both Fish and the Council agree that supervision by the library staff is important as well. Fish said the library staff would ask people to leave if they abuse the Internet.

"If they fail to comply with the request we ask them to leave, and we have banned people from using the library for, say, 30 days when they are repeat offenders," Fish said.