In Campo, Calif., a fence stretches along a desolate area of the U.S.-Mexico border. The federal government wants to install radar, sensors and cameras, but the plan is beset by delays. Campo agents were supposed to be hooked up to the virtual fence in early 2009. (Brian L. Frank for The Wall Street Journal)

The Bush administration created the Secure Border Initiative Network in 2005 to provide real-time pictures of activity along the border. The system was contracted out to Boeing in 2006. More than $600 million later, only a 28-mile-long prototype has been delivered. (Brian L. Frank for The Wall Street Journal)

Frustrated by the delays, citizens -- calling themselves minutemen -- took up the job. They installed 20 cameras, encased in PVC pipe for protection, on a private ranch; they wired them to solar panels and a transmitter that broadcasts the captured images on the Internet. So far, they've spent $40,000 to cover a one-mile strip and fortify fence ranches. (Brian L. Frank for The Wall Street Journal)

"It's tough to keep all the units up and running," said minuteman Howard "Ridgerunner" Smith, a 59-year-old retired mechanic. On a recent day, 16 of their cameras were down due to rainy weather. They don't use their motion detector because it's mostly triggered by wind-stirred vegetation. (Brian L. Frank for The Wall Street Journal)

The government had its own problems: blurry images, radar that couldn't differentiate between people and animals and field agents who couldn't log onto their laptops. The U.S. Customs and Border Protection says the prototype is fixed, but Secretary of Homeland Security Janet Napolitano froze most funding to the project Tuesday. (Brian L. Frank for The Wall Street Journal)