“We cannot rule [out] the ability of future adversaries to acquire and use a commercially available [drone] as part of an attack within the Homeland," according to the assessment issued Friday by the DHS Office of Intelligence and Analysis, or I&A.
The assessment also describes how drug-trafficking organizations use drones to "monitor law enforcement" along U.S. borders and transport loads, even to people inside prison walls.
Like so many other assessments and bulletins issued routinely by DHS, Friday’s 18-page assessment acts more as an "FYI" than a warning to state and local law enforcement.
With recreational use of drones becoming increasingly popular, it will become harder for authorities to detect and stop drones with nefarious intent, according to the assessment.
Since 2012, there have been more than 500 drone "encounters" at sensitive sites across the United States, and 218 of them have been related to the aviation system, the assessment says.
“While many of these encounters are not malicious in nature, they underscore potential security vulnerabilities -- that could be used by adversaries to leverage [drones] as part of an attack," the assessment concludes.