Unless he's on a job, Paul Lopez, a teacher by trade, heads to a 7-Eleven parking lot in Herndon a couple of times a week to wait for work. He was there Friday morning, dressed in paint-stained cargo pants, a shirt, a light jacket and a Washington Redskins cap.

Lopez, who is from Bolivia, said he lives in the United States because he can make "20 times" as much money painting and doing day-labor jobs as he earned in Bolivia teaching elementary, middle and high school. His family remains in Bolivia.

Workers have been a little uneasy coming to the 7-Eleven since day-laborer sites became politically controversial. But for many laborers, that unease has reached a new level.

Representatives of the Herndon chapter of the Minuteman Project, a national group that fights illegal immigration, began showing up last week at the site. On three mornings, including Friday, Minuteman members arrived about 6 a.m. with video and still cameras and walkie-talkies to document the activities of Lopez and other day laborers as well as the employers hiring them.

George Taplin of Herndon, leader of the local chapter of the Arizona-based organization, said the group plans to turn over its data to the Internal Revenue Service, perhaps as early as this week, so the IRS can check whether the employers are complying with tax regulations and reporting the wages paid to the day laborers.

"We are targeting the employers to stop hiring day laborers so we don't have them gathering in Herndon," he said. "If the employers stop coming and there is no work, they will have to go away. . . . What we want, bottom line in Herndon, is for the illegal aliens to leave. And if there is no work, they will."

Lopez said he did not like the Minuteman representatives there. "We are not here to do anything bad," he said through a translator. "We are just here to work. All we want is tranquility. They don't want us to work."

Since summer, when town officials in Herndon began to discuss spending taxpayer money to move the day laborers from the 7-Eleven to a more formal and controlled site, the issue of immigration and the government's role in it has spread from town hall meetings to national talk radio to the Virginia governor's race. The Minuteman group's decision to come to Herndon to monitor the day laborers has brought the debate back to town.

The Town Council approved a new day-laborer site in August, but it is not up and running. Assessments varied on how much impact the Minutemen's presence had last week on the existing gathering spot. Some community workers said the number of immigrants showing up each day might have declined, but it was not clear whether that was attributable to cooler weather and less demand for landscaping work or to the Minuteman Project's presence.

"There may have been some decrease, a little bit, in the number of contractors that are coming in to pick them up," said Edgar Rivera of the Tenants' and Workers' Support Committee, who visited the hiring site Wednesday morning.

Taplin said more than 60 people had joined the group. He said they will continue to monitor and photograph workers and employers, but he would not say how often or when they would be there.

"Does a general tell his enemy when he is going into battle?" Taplin asked.

But he said the group had a successful first week.

"We accomplished more than we set out to do," Taplin said. "The main thing we wanted to do is start building our database with images of the different workers and employers. We also wanted to prove what most people thought, and what we had put forth -- this idea that the vast majority of the people who were there were illegal and the employers were regular employers, not people who came every once in a while looking for workers."

He said members of the group took pictures of workers and employers and then followed the employers to job sites to document the locations. "We found that some vehicles were coming back again and again, serving as taxis, to bring workers to the same work site," he said.

Nancy Mathis, a spokeswoman for the IRS, declined to comment on what the agency would do with the information if the Minutemen handed it over, "because taxpayer information is confidential."

When members of Taplin's group tried to take photographs, workers often turned their backs, Taplin said. He said he took that as a sign that they were in the United States illegally and did not want their pictures taken.

That may not be the case, though.

Many of the workers have attended workshops in recent weeks to prepare them for the move to the new hiring site next month. Among the points they were given on dealing with the Minuteman members and the media was the suggestion that they turn their backs if they did not want to be photographed.

"It really wasn't a workshop specially on the Minutemen," said Bill Threlkeld, director of Project Hope and Harmony, a nonprofit group that will operate the job center. "But certainly, since it is a current issue, it did come up. We just talked about these groups who will try to intimidate with video cameras and that they had a right to take pictures as long as they were in public spaces. The workers don't need to be concerned about that. They can ignore the photographers or just turn around."

As part of the agreement to open a job center, the workers have been told to form a governance team, which they have done, Threlkeld said. He said the team will be involved in the operation of the center, which will open behind the old town police station.

Until the center opens, he said, he has encouraged the workers to communicate with the employers about what is going on at the 7-Eleven site and to use the hiring location as a meeting place to be picked up for scheduled work. He said workers have been told to take down information on the people who hire them to protect themselves in the event they are not paid or are left at job sites, as sometimes happens.

The workers have been given some media-relations pointers, too. "It is important to have a consistent message," Threlkeld said. "They aren't criminals. They are just people who want to work, and they have not come to destroy. They have come to build and help out the community."

For Lopez, the presence of the Minuteman Project is a reminder of how his status has changed. In Bolivia, he said, his position as a teacher made him well known in the community, someone who people looked up to and always greeted warmly on the street. Now he feels like a targeted outcast, he said.

Five or six men gathered around Lopez as he spoke, nodding. "Now I am just a humble worker like every other man here," he said.