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 .
2017 Mexico–United States diplomatic crisis The 2017 Mexico–United States diplomatic crisis is a diplomatic stagnation between both North American nations due to the recent friction between their current presidents. It began when the President of the United States Donald Trump, threatened Mexico with renegotiating the North American Free Trade Agreement because he considers it not to be beneficial to his country, and also said that he would amplify the barrier that already exists between both countries; Mexican President Enrique Peña Nieto said he opposed both proposals. Later, Donald Trump and Enrique Peña Nieto canceled a meeting they had scheduled in Washington D.C.