A lawsuit challenging a federal law that animal rights activists say makes them afraid to participate in public protests has been thrown out by a judge who said the activists have not shown that the law has a chilling effect on their First Amendment rights.

U.S. District Judge Joseph Tauro dismissed a challenge brought by five people who said the 2006 Animal Enterprise Terrorism Act made them fearful of prosecution because it prohibits anyone from intentionally causing the loss of personal property of animal-related businesses or laboratories.

Some activists say a loss of profits could be defined as personal property, meaning that a fur protester who persuades a consumer not to shop at a particular store could be prosecuted.

The law also allows for the prosecution of anyone who "intentionally places a person in reasonable fear of death or serious bodily injury" through threats, vandalism, harassment or intimidation."

Tauro ruled Monday that the protesters had described plans to participate in activities that are not prohibited under the law and had failed to show "an objectively reasonable chill on their First Amendment rights." The judge granted a request by U.S. Attorney General Eric Holder to dismiss the lawsuit.

"Where Plaintiffs seek to engage in lawful and peaceful investigation, protest, public-speaking, and letter-writing, the court cannot reasonably conclude that these actions fall with the purview of a statute requiring intentional damage or loss to property or creation in an individual of a reasonable fear of death," Tauro wrote in his ruling.

The five plaintiffs, represented by the Center for Constitutional Rights, are animal rights activists from around the country who have spent years trying to improve conditions for rabbits, ducks, geese, dolphins and other animals. They have organized anti-fur protests, increased public awareness of slaughter and factory farming, and exposed what they see as cruelties in the foie gras industry.

Rachel Meeropol, a senior staff attorney at the center, said the activists will appeal Tauro's ruling to the 1st U.S. Circuit Court of Appeals.

"While this judge reads the law narrowly in a way that is more protective of the First Amendment, there is no guarantee that other judges will agree or that prosecutors will be respectful of animal rights advocates' freedom of expression. In fact, all the evidence we see is to the contrary, given that there's been a national crackdown on animal rights activists for the last decade or so," Meeropol said.

"Just that possibility of prosecution, of facing a federal terrorism charge is a hugely terrifying, disrupting experience in someone's life," she said.

Sarahjane Blum of Minneapolis, one of the plaintiffs and an active protester against the fur and foie gras industries for more than two decades, said her activities have declined in recent years out of fear that she could be prosecuted under the law.

"I have been looking for avenues where I could continue my activism, even under the kind of stringent chill I feel through the AETA, but I have been having trouble finding ways that I can express myself freely and openly about factory farms," Blum said Wednesday.

The Justice Department did not immediately respond to a request for comment.

The law has been rarely used since it was enacted seven years ago.

In 2009, two activists in Utah were indicted for releasing hundreds of animals from a mink farm. Both pleaded guilty to animal enterprise terrorism and were sentenced to 21 months and 24 months in prison. The same year, four activists were charged for allegedly participating in threatening demonstrations at the homes of University of California scientists who conducted animal research. A judge eventually dismissed the charges.