The US government has had a love-hate relationship with drones for about as long as the technology has been around. On the one hand, the CIA and military love using drones for spying on people and performing controversial "targeted" aerial strikes on declared enemies overseas. On the other hand, lawmakers in Congress have spent the past several years publicly questioning both the overseas drone program and the growing use of small consumer drones by ordinary schmoes back home for aerial photography and other recreational purposes.
It's the latter trend that has Pennsylvania's Republican Congressman Scott Perry spooked. In a hearing on Capitol Hill today, he raised the idea of someone attaching an anthrax-dispersal device to a consumer drone and using it to attack people.
"I'm trying to determine for myself and maybe anybody watching or listening what really the potential worst-case scenario could or would be," Perry said, later describing a hypothetical one thusly: "You put a container, a small container of anthrax or ricin or something like that on even one of these small—less than 55 pounds—[drones]."
"With regard to the dispersal threat… it's almost too cute by half"
Before getting into the feasibility of that idea, some background: Perry, chairman of the Homeland Security Subcommittee on Oversight and Management Efficiency, convened the hearing to ask experts in drone technology, law, and policing about the potential threats posed by consumer drones. Take the popular DJI Phantom series, one of which memorably crashed on the lawn of the White House in January. Although that particular case was a total accident caused by an amateur pilot who was reportedly drunk at the time, it sent the White House and the rest of Washington, DC into consumer drone paranoia overdrive.
Perry himself brought up another White House incident, the report today from The Intercept that an envelope addressed to 1600 Pennsylvania tested positive for cyanide, using it as an example of something that consumer drones could be modified to carry, alongside anthrax or ricin.
"Can you paint a picture for us, maybe not necessarily a worst-case scenario, but an actual probable scenario or possible scenario with somebody with that kind of malicious intent?" Perry asked his panel of experts.
One of the experts present, Pepperdine University law professor Gregory S. McNeal, shot down the feasibility of using small consumer drones to carry out an anthrax attack.
"With regard to the dispersal threat… it's almost too cute by half," McNeal said, adding, "If you really wanted to have a high impact with a WMD, first we have the problem of getting the WMD. But if you have anthrax, that's not the best way to do it. Go to every Starbucks on every corner in DC, sprinkle it into the sugar. Or put it in the sugar shaker on the roof of your car and drive around, and you'll impact a lot more people through that method than you would through the aircraft."
Perry countered with the example of a dispersal drone flying over a crowded stadium filled with thousands of people and the potential mass panic that would result. "You can picture the scene," Perry said.
McNeal politely acknowledged that such a scenario would have a more "psychological impact" than spreading anthrax through sugar, but pointed out "it unfortunately drives policy in a way that's not probabilistic and not possibilistic."
Indeed, anthrax spores need to be inhaled or ingested to cause sickness or death in humans, and spraying them through the air from a drone seems like it wouldn't be the most efficient way to do that, as McNeal pointed out. Plus, although anthrax spores by themselves don't weigh very much, trying to attach enough to a drone to make a bunch of people sick would require a container and release mechanism of some sort, and small drones like the DJI series can't carry that much payload, only a couple of pounds at most.
However, Perry and other members of Congress could be understood for fixating on the threats of a small anthrax drone given the 2001 anthrax letters that killed five people in the US, two of which were mailed to sitting senators at the time.
As for averting other pesky or potentially dangerous drone crashing incidents like the one that actually occurred on the White House front lawn, the experts noted that the first best approach was probably available methods like geofencing—programming no-fly zones into hobbyist drones—which DJI itself did in an update.
One panelist, University of Texas-Austin aerospace professor Todd Humphreys, suggested another novel approach: developing flocks of "interceptor drones" that would use infrared cameras to spot and follow any intruder drones entering sensitive airspace, and then swarm and capture them with nets. While not a catch-all solution, something like that may be necessary to put Congress more at ease as drones become more common.