The house on a quiet, palm-laden street in Beverly Hills seemed an unlikely terrorist target. But in the early morning hours of February 5, a masked man crept toward the multimillion-dollar home on Shady Brook Drive and wedged a Molotov cocktail against the front door. The device ignited, sparked a fire, and charred the entranceway black with soot. No one was home or hurt. The Federal Bureau of Investigation, the lead agency on the case, has been mum on the status of the intended victim: Dr. Edythe London, professor of psychiatry and a biomedical scientist at the University of California, Los Angeles, where she uses non-human primates to study nicotine addiction.

It is known that the suspects, now fugitives, are animal rights extremists with ties to the Animal Liberation Front (ALF), one of a handful of belligerent underground groups that have splintered from the larger and lawful animal rights movement. First Amendment defenders bristle at the characterization, but the FBI designates activists who resort to arson or explosives as “domestic terrorists” and a serious threat to homeland security. Working with the same Joint Terrorism Task Force tracking Al Qaeda’s terrorist cells, the FBI now has special agents in 35 of its field offices—from San Francisco to Baltimore—devoted to hunting and prosecuting animal rights and environmental extremists.

The February firebombing at London’s home, one of some 200 separate extremist cases currently under investigation in the United States by federal agents, marked the second time extremists had targeted London. The first attack occurred on a windy Saturday night in October, when prowlers snuck into the backyard of London’s hillside abode, smashed a window, and, after clogging an intake drain in the swimming pool, inserted a garden hose, running it at full blast. It is unclear how many hours passed before the ground floor flooded, but the vandals caused at least $30,000 in damage.

Several days later, the ALF took credit for the vandalism in an anonymous “communiqué,” as extremists call the announcements. It was posted online by the Animal Liberation Press Office, a legitimate group unrelated to the ALF, but used to publicize what animal activists call “direct actions,” guerilla tactics used to commit illegal attacks. The ALF, which insists it never harms people or animals, included a personal message for London. “One more thing Edythe,” the perpetrators said in an October 25 communiqué about the flood. “Water was our second choice, fire was our first…. It would have been just as easy to burn your house down Edythe.”

The group warned: “Until we see the end of primate vivisection at UCLA, we will remind you of our presence. Push them to stop Edythe or we keep pushing.” That never-stop-until-we-win sentiment was echoed in an ALF communiqué dated February 21, when the activists took credit for the firebombing weeks earlier. “Now is the time to stop vivisecting. We don’t back down. Ever.”

In the past 10 years, there has been a surge in attacks against biomedical research scientists, whether they work for multinational corporations, private animal laboratories, drug companies, or academic institutions. Biotech and pharmaceutical researchers and CEOs—along with their spouses, children, neighbors, and friends—have been harassed (somewhere in the world almost daily) by threatening telephone calls, nasty emails, and vulgar letters. For many targets, personal privacy goes out the window as activists use the Internet to publicize personal details about their lives—home addresses and Social Security, credit card, and checking account numbers. The online information dumps often are accompanied by pleas for comrades to go on the attack. Midnight and pre-dawn lawn protests are part of the movement’s regular repertoire.