The recent undercover operation by People for the Ethical Treatment of Animals at AgriProcessors Inc., a kosher slaughterhouse in Postville, Iowa, was a public-relations coup for the militant animal-rights group. A volunteer who got a job at the plant used a hidden camera to videotape the slaughter of animals, which PETA posted on its website in late November. In one stroke, the activists simultaneously managed to sicken people with graphic images of animal carnage and enrage them about the practices of Jewish ritual slaughter, or shechitah. To boot, the group promoted itself as the fearless and innovative champion of animal...