A new battle unfolding at the southern border as cartels change the way they watch the Americans securing the country's sovereignty, replacing lookouts with drones that can track Border Patrol movements from above. Federal officials say the drones are being used for reconnaissance during drug smuggling and human trafficking operations, giving criminal groups another way to monitor where agents are operating. Some drones have also been used to carry drugs across the border. @​Max Gorden reports how federal forces are fighting back, with the Department of War working with DHS to detect and bring down unauthorized drones. Download the FOX News app for the latest details: ▻