Over 1,000 drones per month are crossing into US airspace near the border with Mexico, a US top general told lawmakers on March 14. The number of unmanned drone incursions is “alarming” and presents a “growing” potential threat to national security, said the general. Air Force Gen Gregory Guillot warned of the “potential threat” during a Senate Armed Services Committee hearing. When asked about the timeframe for his estimation, Guillot replied: “We can probably have over 1,000 a month.” Watch the video to find out how Mexican cartels are using drones to track the US border authorities.