Hundreds of Americans have begun patrolling one of the most porous sections of the U.S.-Mexico border: 37 kilometers in southwest Arizona, looking for drug smugglers, potential terrorists, and illegal immigrants.
Posted every 600 meters along the border, the volunteers who call themselves Minutemen, including Larry Morgan, are on a mission.
"We're trying to shut down the border, slow down the invasion of illegals," says Mr. Morgan.
That's something they say the 2,200 U.S. Border Patrol agents assigned to Arizona have never accomplished.
So 400 mostly-retired men and women have strapped on sidearms, pulled up lawn chairs, dodged rattlesnakes, and trained their binoculars on Mexico.
"We observed small groups of people with backpacks," says a Minuteman.
They called in the Border Patrol and took no further action.
So far, there have been only a handful of sightings. Organizer Chris Simcox says that is proof the operation is working.
"It was so well-advertised, it worked, it's a deterrent," says Chris Simcox.
But the Border Patrol says there's another reason - Mexican military operations on the other side of the border.
Andy Adame, with the U.S. Border Patrol says, "And whenever they've had those operations in the past, we've always seen apprehensions drop significantly."
Human rights groups and local residents are worried there could be vigilantes among the Minutemen, who could injure others or end up being hurt themselves. In the mostly Hispanic border towns here, tensions are running high.
Ray Borane is the mayor of Douglas, Arizona.
"They have a lynch mob mentality especially when it comes to dealing with illegals," says the mayor.
So far, there have been no confrontations, and no shots fired. However, the Border Patrol says people are still illegally crossing the border at numerous places.