BERKELEY, Calif. | In the hills above the University of California's Berkeley campus, nine protesters gathered in front of the home of a toxicology professor, their faces covered with scarves and hoods despite the warm spring weather.
One scrawled "killer" in chalk on the scientist's doorstep, while another hurled insults through a bullhorn and announced, "Your neighbor kills animals." Someone shattered a window.
Animal rights activists are increasingly taking their rage to scientists' front doors.
Over the past couple of years, more researchers who experiment on animals have been harassed and terrorized in their homes, with weapons that include firebombs, flooding and acid.
Scientists say the vandalism and intimidation threaten themselves, their families and the future of medical research. Specialists in fields such as addiction, eyesight and the aging brain have been targeted.
"It used to be everyone was worried about their laboratories being broken into and their data being destroyed, their animals being taken away," said Jeffrey Kordower, head of the Society for Neuroscience's animal research committee. "What they've decided to do now is make things more personal."
Accompanying the attacks is increasingly tough talk from activists such as Jerry Vlasak, a spokesman for the Animal Liberation Front press office. In an interview with the Associated Press, he said he is not encouraging anyone to commit homicide, but "if you had to hurt somebody or intimidate them or kill them, it would be morally justifiable."
The Washington-based Foundation for Biomedical Research said researchers were harassed or otherwise victimized more than 70 times in 2003, up from 10 a year earlier. The number of attacks has held steady or risen since, according to the group.
Activists say the escalation in tactics results from a frustration that nonviolent methods have failed to stop what they call the needless torture and killing of animals.
"An animal has as much of a right to life as we do. To take a life without provocation is immoral, it's violent, there's no excuse for it," said Jacob Black, 23, an organizer of demonstrations at the homes of UC Berkeley researchers. "To name and shame these people as morally bankrupt individuals in our society is key."
A Web site aimed at Berkeley lists the names of a dozen researchers and their home, work and e-mail addresses, their photos, and often their home numbers. The roster also includes graphic descriptions of each scientist's purported work with animals.
"This information is here so that others may pressure these individuals with legal protests - we do not participate in or encourage illegal activity," the Web site says.
Despite that disclaimer, the late May protest in the Berkeley hills left a window of the toxicology professor's home shattered along with the window of a neighbor, who sprayed a garden hose to drive away demonstrators.
Many scientists worry that any sign the attacks are succeeding could just lead to more of the same.
In 2006, activists began besieging the homes of several professors at the University of California at Los Angeles. Masked protesters converged on scientists' homes late at night, banging on doors, throwing firecrackers and chanting, "We know where you sleep," according to court documents.
Threatening calls and e-mails followed. Firebombs were left near homes three times; two failed to go off, while the third charred a front door. One professor's home was flooded when a garden hose was shoved through a broken window.
Though no one has been seriously hurt since the jump in home protests, the attacks have drawn the attention of the FBI. The agency has broad authority to investigate animal rights incidents under the Animal Enterprise Terrorism Act of 2006.
"We consider this to be a serious problem, especially when people's lives are being disrupted," said agent David Strange, who oversees a domestic counterterrorism squad at the FBI's Oakland office. "We call it terrorism because it is a violent act violating federal criminal laws that has a political or social motivation to it."