Updated

More than a thousand Americans have descended on a remote stretch of the U.S.-Mexican border to join a group that calls itself the Minutemen (search), which claims to be dedicated to stopping illegal immigration, but which others call racist.

"Just a month previous to hearing about this, I said to a co-worker that I would be more than willing to spend a vacation to protect the borders," said one Minuteman.

Part public-relations stunt, part political theater, the makeshift border patrol has already had an impact. The activists have virtually closed down a popular pipeline used by people smugglers.

This weekend, the Minutemen spotted 118 illegal aliens trying to cross the border.

"Our laws are being broken, our borders are being penetrated," said one Minutewoman.

But the American Civil Liberties Union (search) and some Hispanic organizations are keeping an eye on the Minutemen, fearing they will violate the individuals' human rights.

"They're coming into Arizona with guns and they're threatening violence and harming people," said a protester.

Two weeks ago, President Bush, who supports a guest worker program (search) that would allow illegal immigrants to stay in the United States, called the Minutemen "vigilantes."

"I am against vigilantes in the United States of America; I am for enforcing law in rational ways," Bush said during a press briefing with Mexican President Vicente Fox and Canadian Prime Minister Paul Martin.

Some who say they are protecting the border take exception to Bush's characterization.

"I was really disturbed that we were called 'vigilantes' by our president. We really don't feel that way, and that's not our statement and that's not who we are," said another Minuteman.

Cochise County (search) in Arizona is the size of Connecticut. Border Patrol agents acknowledge that they needs more help, but say they fear the Minutemen will do more harm than good.

"They're a bunch of civilians out there wandering aimlessly through the desert, setting off sensors. Our agents are having to respond to those sensors thinking it's an illegal alien," said Border Patrol agent Andy Adame.

The Minuteman Project is having an impact. Smugglers tell the Mexican press that crossing in the area where the Minutemen are patroling is now impossible and they have to go elsewhere or wait 30 days until the Minutemen are gone.

About 66,000 illegal immigrants were caught last month in one area where the Minutemen were offering back-up patrol. At that rate, the equivalent of the population of Indianapolis would be apprehended over a year.

The presence of the Minutemen is unlikely to solve the problem of illegal immigration into America, but the volunteers say that even if they can't stop it all, they predict that the publicity will raise awareness of the open border and force Bush to rethink a proposal that many of his core supporters oppose.

Click in the video box above for a full report by FOX News' William La Jeunnesse.