A host of experts from all walks of life have weighed in about the recent animal-rights firebombing of a Santa Cruz, California biomedical researcher’s home (with his children inside). Yesterday, in the scientist’s hometown Santa Cruz Sentinel, we had our say. If you want to understand how people who claim “kindness to animals” as their rallying cry can embrace cruelty to people so quickly, we wrote, think about what the animal rights movement actually stands for—and listen to what a few of its leaders have been saying:

The animal rights philosophy is by its nature an extreme religion. Its disciples believe deep down that animals are “people.” Their call to faith is that their movement is heir to the struggles of civil rights and women’s suffrage. They fervently believe the rights of “non-human animals” are equal to the rights of humans. Without exception.

So it makes perfect sense that there is no limit to the violence they will propagate. They claim, “If you saw your own children in cages, what would stop you from freeing them?” Bloody wars have been waged over less. For the animal rights fringe, there is no moral or philosophical line separating my 4-year-old daughter and a chimpanzee. Or even a mouse.

Knowing that animals are being used for research -- or raised for food, exhibited in zoos, or snared on the end of a fishing hook -- stirs up turbulent feelings among such activists that most of us reserve for concern about our own species.

Not even the so-called mainstream of the animal protection movement is immune. “Blowing stuff up and smashing windows [is] a great way to bring about animal liberation,” People for the Ethical Treatment of Animals (PETA) vice president Bruce Friedrich told a convention in 2001. “Hallelujah to the people who are willing to do it.”

And Jerry Vlasak, then a spokesman for the wing-nuts at the PETA-affiliated Physicians Committee for Responsible Medicine, advocated the “political assassination” of animal researchers in 2003. “For 5 lives, 10 lives, 15 human lives,” Vlasak intoned, “we could save a million, 2 million, 10 million non-human lives.”

It continues to be difficult to draw a line between “peaceful” animal rights advocates and menacing promoters of violence. As we recently pointed out in the Las Vegas Review-Journal, even the Humane Society of the United States has a personnel connection with the terrorist Animal Liberation Front. (A former ALF spokesman is on HSUS’s senior staff.)

PETA, PCRM, and HSUS—all soybeans in the same pod—shouldn’t be trusted until they fully explain their ties to violence and sever every tie to the animal rights movement’s vicious underbelly. But somehow we suspect their quasi-religious fervor will always outweigh the need for an honest accounting of how the “kindness” racket became so very, very unkind.