Which structure currently operates as a "virtual fence:"  Boarder Wall or Mexico-United States Barrier?
Mexico–United States barrier The Mexico–United States barrier is a series of walls and fences along the Mexico–United States border aimed at preventing illegal crossings from Mexico into the United States. The barrier is not one continuous structure, but a grouping of relatively short physical walls, secured in between with a "virtual fence" which includes a system of sensors and cameras monitored by the United States Border Patrol. As of January 2009, U.S. Customs and Border Protection reported that it had more than 580 mi of barriers in place. The total length of the continental border is 1,989 mi .
Gateway International Bridge Gateway International Bridge is one of three international bridges that cross the U.S.-Mexico border between the cities of Brownsville, Texas, and Matamoros, Tamaulipas. It is owned and operated by Cameron County. Over the past century, it has developed the nickname of "The New Bridge" when the bridge was remodeled back in the 20th century. Despite the fact that the Veteran's International Bridge is newer than Gateway, it still retains its nickname.