The Department of Homeland Security's latest version of a border "virtual fence" has suffered another setback. TUCSON, Ariz. — The Department of Homeland Security's latest version of a border "virtual fence" has suffered another setback — prompting Secretary Janet Napolitano to order a departmentwide reassessment of the program. Officials expected to have a 17-tower system up and working along 23 miles of the U.S.-Mexico border flanking Sasabe, Ariz., by the end of 2009. But the handover to the Border Patrol has been delayed at least three more months. The Sasabe grid is the first in a series of virtual fences...