Organizers of the Minuteman Project (search) will watch the border for a month and report sightings of illegal activity to Border Patrol agents.
Minuteman field operations director Chris Simcox (search) described the project as "the nation's largest neighborhood watch group" and said one of the goals is to make the public aware of how porous the border is.
Jim Gilchrist, a retired accountant from Aliso Viejo (search), Calif., who organized the project, said some volunteers will carry handguns, which is allowed under Arizona law, but are being instructed to avoid confrontation, even if shot at.
Still, law enforcement officials and human rights advocates are worried about the potential for bloodshed.
Critics contend the project may attract anti-immigrant racists and vigilantes looking to confront illegal immigrants. At least one white supremacist group has mentioned the project on its Web site.
"They are domestic terrorists that represent a danger to the country and could promote a major border conflict that will have serious ramifications and consequences," said Armando Navarro, a University of California-Riverside political science professor and coordinator of the National Alliance for Human Rights, made up mostly of Hispanic activists.
simular events are already in place in texas and new mexico.