Such drones would be a dandy way to deliver a biological or chemical weapon.
FTA:
Fifteen agricultural spray drones were stolen from a New Jersey location last month in what the FBI is treating as a sophisticated, possibly coordinated theft, according to reporting by national security journalists Jack Murphy and Sean D. Naylor at The High Side. The case is unsolved. Retired FBI agent Steve Lazarus told the outlet the bureau is "freaked out for a good reason,” warning that the machines are "industrial sprayers designed to carry and disperse significant amounts of liquid quickly and with precision.”
If this is the Iranians we could wind up with some very bad things happening soon.
Also, government regulations make replacement of such drones nigh unto impossible, and the legal owners are now in dire straits as they bought them out of need and now have none. Fear of such drones being used as weapons led to a near ban on them.
Fifteen drones disappearing suggests more than simple theft. Each weighs up to 150 lbs and they are large enough that it would take a substantial truck to take them.
One has to wonder if there is any connection to the huge drones seen over New Jersey and other places last year. The government denied these were anything but hobbiest drones, but eye witnesses vehemently disagreed.