The use of commercial drones is increasing so fast that companies are now developing counter measures.
From celebrities being photographed in their homes to criminals using it to smuggle drugs and weapons inside jails, drones raise new concerns for privacy and security.
That's why U.S.-based company DroneShield developed a tool aimed at detecting nearby drones.
Every drone produces a unique sound when it flies – its signature. The DroneShield, a small rectangular device paired with a number of microphones, listens to ambient sounds and checks them against a database of known signatures. If there is a match – meaning a drone is detected – the device sends a text or an email to warn the user of the drone's proximity.
Since 2011, two drones have been seen flying over Quebec jails. Three others were seized, according to documents obtained by La Presse.
While Correctional Services Canada refused to comment on any security measures implemented to counter illegal drone activity, it is looking for ways to detect drones.
"We have done demonstrations for CSC, but no purchases [have been made] yet," confirms Brian Hearing, co-founder of DroneShield.
So far, his company has done over 150 installations across the world. The RCMP and the Vancouver International Airport also contacted him, but no purchases have been made yet.
In July of 2013, a WestJet pilot reported seeing a drone flying next to his aircraft while landing at the Vancouver International Airport. A similar incident happened to an Air Canada pilot at the same airport.
Depending on the ambient noise level and the microphones used, the device can detect drones from 150 metres up to a kilometre.
"With prisons, we have 10-12 sensors typically, so it is setup like a 'clock,'" explains Mr. Hearing, a setup that allows to pinpoint the drones location more precisely.
His customers are largely individuals, like citizens concerned about harassment and voyeurs.
Drones may be easy to detect, but they are much more difficult to stop.
"I don't think there is a really a solution on how to bring them down," admits Mr. Hearing.
While his company sells net guns that can capture a drone by casting a net around it, this only works at very close range, according to Mr. Hearing.
He discourages anyone from trying to shoot down a drone with a firearm, which is both illegal and ineffective given the target size.
In Canada, even if a drone trespasses on a property, the only thing that can be done legally is to call the local police force, an RCMP spokesperson confirmed.
"We believe the answer lies in prosecuting the operator," said Mr. Hearing.
While there are effective ways to disrupt a drone, like jamming its frequencies so the pilot can't pilot it anymore, most of methods remain illegal.
Strobing lights can be used to ruin photographer's shots, but, again, it won't bring the drone down.
Last April, a drone got caught in the barbed wires of a South Carolina jail. But those wires are meant to prevent helicopters break out and drones can simply drop off their package well above the wires.
In an email, Transport Canada reiterated that all Unmanned Aerial Vehicle (UAV) operators must abide by the law, writing: "If a person believes their safety is at stake, they can file a report to Transport Canada."
DroneShield started when the Mr. Hearing's business partner, John Franklin, used a drone to inspect his house roof and mistakenly landed it in his neighbour's backyard.
"He could see right into their kitchen, and the neighbour didn't know it," said Mr. Hearing.
As both of them have a background in defence, detecting helicopters and tanks, they saw the potential for DroneShield.
The market for drone counter-measures is still relatively small. Beyond DroneShield, only two other companies sell similar products.
Domestic Drone Countermeasures, a U.S. company, manufactures a device that relies on the radio transmissions between the drone and the pilot for detection.
Paris-based Drone-detection sells a device similar to DroneShield, analyzing ambient sound to detect drones.
Mr. Hearing insists he isn't against drones themselves.
"It's just another technology that could be used to commit crimes," he said.
In the end, the sky is public property, says Mr. Hearing.
"You can't shoot down an airliner because it's over your house."