Mason said she believes the best way to protect abortion rights is to analyze the method of abortion opponents.

"I do not believe that the escalation of violence is a conspiracy but it is not isolated either," she said.

Mason cited what she called the "guerilla warfare" nature of abortion opponents, some of whom use domestic terror tactics to create an environment to endanger women's rights, as evidence of such violence.

While Mason has centered her work in Cambridge for the last year, she spent last week in Buffalo, observing Operation Rescue rallies at clinics.

Last October, Dr. Bernard Slepian, who worked at a Buffalo clinic, was shot to death by a sniper at his home.

"They do function symbolically together to make abortion increasingly physically, mentally and emotionally more difficult," she said of abortion opponents who use violence.

For McDowell, his experiences have shown him the lighter sides of abortion-opponent extremists.

"It's entertaining to talk to them. There are some seriously disturbed people out there," he said.

Although he is sometimes amused by his experiences, ultimately he said the active protestors are not only violating the rights of women seeking an abortion, but their rights just to enter clinics.

"It's none of their business, but they make it their business," he said. "They think they know a lot more than they do."