CHICO, Calif. -"Meat is murder," activists from the Animal Liberation Front scrawled on a McDonald's restaurant here last month.

Two crude incendiary devices failed to ignite, but a second McDonald's in this Sacramento Valley college town was damaged a week later by burning debris. A day later, two Albuquerque, N.M., McDonald's and an Arby's were firebombed, with police suggesting similar ties to the nation's most active, destructive domestic terrorists.

The Golden Arches have been hit abroad as a symbol of the United States' corporate dominance and encroaching lifestyle. But the fire bombings of the ubiquitous hamburger restaurants at home have hit a jarring note with company officials and law enforcement nationwide.

An Earth Liberation Front promotional video called "Igniting the Revolution" features McDonald's among its corporate targets. The FBI labels the elusive, loosely knit shadow organizations the nation's most active and destructive domestic terror groups, responsible for more than $43 million in damage in more than 600 attacks since 1996.

"They're going after the wrong people, because we have an exemplary record when it comes to animal welfare," said McDonald's Corp. spokeswoman Lisa Howard.

McDonald's launched a public relations effort in response, erecting racks of brochures at its restaurants and information on its Web site touting its social and environmental stewardship.

That's not good enough for ALF and ELF, said Rodney Coronado, a former ALF member who spent more than four years in prison for a 1992 fire bombing of animal research laboratories at Michigan State University.

"Wherever they are, McDonald's are a legitimate target for people who want to protect the earth," Coronado said. "McDonald's is a symbol of international animal abuse and environmental destruction."

Coronado demonstrated a device similar to that used in the Chico attack at a January conference at Washington, D.C.'s American University. Directions on building the devices also are on ALF's and ELF's Web sites, enabling activists to encourage copycat arsons without having direct knowledge of the crimes.

"It's a way we can insulate ourselves - there's no signature device. It's a crude, inexpensive device that can be very effective," Coronado said, though the ones in Chico fizzled.

Ron Arnold of the Center for the Defense of Free Enterprise in Bellevue, Wash., said the elusive attacks leave McDonald's Corp. in a state of denial as it juggles more than 30,000 restaurants in 118 countries serving 46 million customers a day.

It downplays attacks for fear of frightening customers and shareholders, said Arnold, author of "EcoTerror: The Violent Agenda to Save Nature-the World of the Unabomber."

David Martosko, research director for the Washington, D.C.-based Center for Consumer Freedom, said McDonald's attacks that get publicity are "literally the tip of the iceberg."

"I think McDonald's has made itself vulnerable in a certain way by its history of capitulating" to aboveground animal rights groups like People for the Ethical Treatment of Animals, said Martosko, whose organization represents restaurants and food manufacturers.

PETA has embarrassed several fast-food chains into altering their practices, but "McDonald's was really the first to respond by saying, 'OK, we'll do things your way,'" Martosko said. "To my mind, that sends a message to the entire social movement that you can be pushed around here."

Factory farms, slaughterhouses and animal research facilities all might be closer to animal cruelty, and all have been targeted by animal rights groups.

But people identify far more with their local McDonald's, said Gary Perlstein, a professor emeritus at Oregon's Portland State University and board member of the watchdog group Stop Eco-Violence.

"A terrorist group is always going to attack the symbol," Perlstein said. "McDonald's will be a target until they only sell vegetable sandwiches."

ALF and ELF are closely affiliated and brag about their attacks through aboveground intermediaries like Coronado. Yet the groups frustrate investigators who say they have no structure, operating in anonymous cells that commit copycat crimes and then disappear.

Two weeks before the Chico attacks, Coronado appeared at a conference for radical activists at California State University, Fresno, 230 miles south of Chico.

He now divides his time between Tucson, Ariz., and Northern California, and plans to be back in Fresno next week giving a seminar to prospective tree-sitters who want to protest logging by Pacific Lumber Co. along California's North Coast. His involvement in those protests has enabled Pacific Lumber to suggest the pacifist protesters there are allied with ecoterrorists.

While Coronado encouraged property damage aimed at corporations, he emphasized ALF's and ELF's credo of avoiding injuries or death to humans or animals. He denounced as aberrations recent violent statements by ELF and former ELF spokesman Craig Rosebraugh that law enforcement officials fear may signal a change in the group's philosophy.

"We as a movement are brought up to be nonviolent," Coronado said. "We know the repression that awaits people who use physical violence."

Regardless of intent, law enforcement officials said it's only a matter of time before someone is hurt or killed, perhaps fighting one of the groups' arson fires.

Yet the groups' distinction between damaging property and harming people has helped make them successful, particularly in university environments where they flourish, said Perlstein.

"Because a lot of people agree with the goal - the protection of animals - they have a hard time agreeing that the activities of ALF or ELF are terrorism," Perlstein said. "They just refuse to put the same label on this as they do al-Qaida."