Each day, 3600 border patrol agents roam the desert border with Mexico trying to stem the human tide of thousands of illegal immigrants that daily attempt to cross over from Mexico.
In 2006, an invisible fence using high-tech radar towers was proposed as the answer to illegal immigration in the United States. It's called SBI net, known to most along the Arizona border simply as the "virtual fence."
Watch A Special Edition of World News With Diane Sawyer From Phoenix, Arizona For More On This Story.
Boeing was brought in to build the surveillance system in southern Arizona. It was intended to be a high-tech wonder linking sophisticated monitoring technologies to the Border Patrol to help identify and thwart human trafficking and drug smuggling. Towers with the radar system were supposed to be erected throughout the 2000 mile border with Mexico. From the start, there were technical issues.
Just four years since its inception, only 53 miles of the border are dotted with the spotty radar towers. Close to $1 billion of taxpayer money has been spent and the panned project is close to being canned by the Department of Homeland Security.
"We cannot continue to invest hundreds of millions of dollars of taxpayer money into something if we're not confident it's really going to work," Secretary of Homeland Security Janet Napolitano said.
What was supposed to be a high-tech answer to immigration has turned into a jumble of weak cameras providing blurry images, unreliable radar that sometimes confuses cars for humans, and slow software that is unable to track people in real-time. And on top of all of that, the virtual fence reportedly performs poorly in bad weather.
Arizona politicians, channeling the frustration of their constituents, feel the same as the government.
"The virtual fence has been a complete failure," Sen. John McCain of Arizona said.
Boeing's contract with the Department of Homeland Security is due to expire Nov. 21. The company, which has received most of the $850 million in taxpayer money spent on the project, seems to be in denial.
The company issued this statement: "[Boeing] stands behind its work on the SBI net system as a reliable, effective border security tool."
In 2008, Boeing claimed the system helped catch 2,000 illegal immigrants in just 5 months. In Nogales, Arizona, agents averaged 2000 apprehensions every two days without the help of a virtual fence. Many say the success of border patrol agents in Nogales raises questions about the cost-effectiveness of the virtual fence.
Many of those currently protecting the border believe there is no technology, regardless of cost, that can replace boots on the ground.