ABC News 11/26/17:
Terror threat to US rail puts law enforcement on alert
With terrorist groups renewing calls for would-be attackers to target American rail lines, at least one local law enforcement agency in the U.S. is using drones to help guard against such a threat.
The police chief for the Philadelphia-area's mass-transit system said he has known for some time that more than 140,000 miles of rail lines crisscrossing America are "porous" and had thought for a while of using drones to monitor the agency's tracks.
He initiated the drone program after an article in the latest issue of al Qaeda's English-language publication gave step-by-step instructions for fashioning a "homemade derail tool" and claimed that railroads are among America's "easiest targets."
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