German Defence Minister Ursula von der Leyen walks past a Heron drone during a visit to Camp Castor in Gao, Mali, December 19, 2016. REUTERS/Kay Nietfeld/Pool 

A Russian soldier launches a drone during a joint Serbian-Russian military training exercise "Slavic Brotherhood" in the town of Kovin, near Belgrade, Serbia November 7, 2016. REUTERS/Marko Djurica 

A Mercedes drone is seen in Stuttgart, Germany September 7, 2016. Daimler is spending about 500 million euros ($562 million) over the next five years on developing new business models for its vans segment, including last mile delivery services by drone. REUTERS/Edward Taylor 

Britain Sailing - America's Cup 2016 - Portsmouth - 23/7/16
Film crew trying to catch a drone during the racing
Reuters / Henry Browne
Livepic 

Keller Rinaudo, CEO and co-founder of Zipline International, speaks during a presentation at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

Eduardo Martinez (L), president of UPS Foundation, and Keller Rinaudo, CEO and co-founder of Zipline International, speaks during a presentation at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

Engineers carry a fleet of Zipline aerial delivery drones before a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A Zipline delivery drone sits on a work bench at an undisclosed location during a flight demonstration in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A Zipline delivery drone launches from its launcher during a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

John Schwindt, an engineering technician with Zipline International, performs a preflight inspection on a delivery drone during a demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

Brett Alo, an aerospace technican with Zipline International, places a Zipline aerial delivery drone on its launcher during a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

Keenan Wyrobek, head of product engineering at Zipline International, displays a package of fake blood airdropped by a Zipline drone during a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A Zipline delivery drone sits on a work bench at an undisclosed location during a flight demonstration in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

An iPad displaying flight status of the Zipline aerial delivery drone is seen during a demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A Zipline delivery drone flies by the drop zone after releasing its payload during a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A carbon fiber fuselage of a Zipline delivery drone sits on a work bench at an undisclosed location during a flight demonstration in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A propeller mounted to a Zipline delivery drone is seen at an undisclosed location during a flight demonstration in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

Eric Watson, a systems engineer with Zipline International, loads a payload into a Zipline aerial delivery drone during a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A Zipline delivery drone sits inside a modified shipping container before a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A Zipline delivery drone releases its payload midair during a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A Zipline delivery drone launches from its launcher during a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

Ryan Oksenhorn, a software engineer with Zipline International, carries a Zipline aerial delivery drone before a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A Zipline delivery drone climbs after releasing its payload midair during a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A Zipline delivery drone releases its payload midair during a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam TPX IMAGES OF THE DAY 

A Zipline delivery drone sits on a work bench at an undisclosed location during a flight demonstration in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A Zipline delivery drone launches from its launcher during a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

John Schwindt, an engineering technician with Zipline International, performs a preflight inspection on a delivery drone during a demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

Keenan Wyrobek, head of product engineering at Zipline International, displays a package of fake blood airdropped by a Zipline drone during a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

Brett Alo, an aerospace technican with Zipline International, places a Zipline aerial delivery drone on its launcher during a flight demonstration at an undisclosed location in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A Zipline delivery drone sits on a work bench at an undisclosed location during a flight demonstration in the San Francisco Bay Area, California, U.S., May 5, 2016. REUTERS/Stephen Lam 

A police drone flies over the scene of a damaged Volkswagen car in the Bismarckstrasse in Berlin, Germany March 15, 2016. German police said on Twitter that they believe an explosive device caused a car to explode while it was driven along a road in central Berlin on Tuesday morning. REUTERS/Fabrizio Bensch 

Members of the Russian Emergencies Ministry take part in a training session, part of the preparation for Russian Orthodox Epiphany celebrations, on the suburbs of Moscow, January 13, 2016. Orthodox believers will mark Epiphany on January 19 by immersing themselves in icy waters regardless of the weather. REUTERS/Maxim Zmeyev 

Members of the Russian Emergencies Ministry take part in a training session, part of the preparation for Russian Orthodox Epiphany celebrations, on the suburbs of Moscow, January 13, 2016. Orthodox believers will mark Epiphany on January 19 by immersing themselves in icy waters regardless of the weather. REUTERS/Maxim Zmeyev TPX IMAGES OF THE DAY

Intel CEO Brian Krzanich talks about the new Yuneec Typhoon H drone, which he said was the first consumer drone equipped with Intel's RealSense sense and avoid technology, during his keynote address at the Consumer Electronics Show in Las Vegas January 5, 2016. REUTERS/Rick Wilking 

Intel CEO Brian Krzanich holds up a new Yuneec Typhoon H drone, which he said was the first consumer drone equipped with Intel's RealSense sense and avoid technology during his keynote address at the Consumer Electronics Show in Las Vegas January 5, 2016. REUTERS/Rick Wilking TPX IMAGES OF THE DAY

Workers set up a commercial drone display at the AEE Technology booth in the Las Vegas Convention Center during set-up for the 2016 CES trade show in Las Vegas, Nevada, January 5, 2016. In the foreground is a F600 all-weather, carbon fiber drone. The large size means the the drone can carry a larger payload and has better stability in wind, a representative said. REUTERS/Steve Marcus 

Representatives from the French company Parrot demonstrate a prototype of their new Disco drone at the opening event at the Consumer Electronics Show in Las Vegas January 4, 2016. The Disco is the first wing-shaped drone which a user can pilot with no learning process, according to the company. REUTERS/Rick Wilking 

A drone with a camera follows Ronan Chabot of France as he drives his Toyota through the water during the Buenos Aires-Rosario prologue stage of Dakar Rally 2016 in Arrecifes, Argentina, January 2, 2016. REUTERS/Marcos Brindicci

DJI's first flagship store is pictured in Shenzhen, Guangdong province, China December 20, 2015. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

A customer carrying a box containing DJI's Phantom 3 drone leave from their first flagship store in Shenzhen, Guangdong province, China December 20, 2015. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

Customers look at a DJI's Phantom 3 drone at their first flagship store in Shenzhen, Guangdong province, China December 20, 2015. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

DJI's first flagship store is pictured in Shenzhen, Guangdong province, China December 20, 2015. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

Customers line up to buy DJI's drone at their first flagship store in Shenzhen, Guangdong province, China December 20, 2015. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

Customers look at a DJI's Phantom 3 drone at their first flagship store in Shenzhen, Guangdong province, China December 20, 2015. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

A DJI's Phantom 3 drone flies during a demonstration at their first flagship store in Shenzhen, Guangdong province, China December 20, 2015. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

A DJI's Phantom 3 drone flies during a demonstration at their first flagship store in Shenzhen, Guangdong province, China December 20, 2015. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

A child looks at DJI's Phantom 3 drone at their first flagship store in Shenzhen, Guangdong province, China December 20, 2015. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

Customers line up to buy DJI's drone at their first flagship store in Shenzhen, Guangdong province, China December 20, 2015. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

DJI's Phantom 3 drones are displayed at their first flagship store in Shenzhen, Guangdong province, China December 20, 2015. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

A woman walks past a shelf display of DJI's Phantom 3 drones at their first flagship store in Shenzhen, Guangdong province, China December 20, 2015, two days before it's official opening. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

DJI's Phantom 3 Professional drone is displayed at their first flagship store in Shenzhen, Guangdong province, China December 20, 2015, two days before the official opening. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

A customer holds a DJI's Phantom 3 Standard drone at their first flagship store in Shenzhen, Guangdong province, China December 20, 2015, two days before the official opening. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

DJI's Phantom 3 Professional drone is displayed inside DJI's first flagship store of DJI in Shenzhen, Guangdong province, China December 20, 2015, two days before the official opening. Chinese drone developers are racking up an impressive list of aerial solutions for a growing variety of demands, from police surveillance to agricultural mapping and traffic management. Already well established as a world leader in drone manufacturing, China is slowly emerging as a world-class innovator, not just a duplicator of foreign designs. REUTERS/Tyrone Siu 

Muthanna Islamic Movement members inspect what they say is a Russian made military surveillance drone which they claimed to have shot down in Sheikh Meskeen near Deraa, Syria December 15, 2015. Picture taken December 15, 2015. REUTERS/Alaa Al-Faqir 

Muthanna Islamic Movement members inspect what they say is a Russian made military surveillance drone which they claimed to have shot down in Sheikh Meskeen near Deraa, Syria December 15, 2015. Picture taken December 15, 2015. REUTERS/Alaa Al-Faqir 

A Muthanna Islamic Movement member inspects what they say is a Russian made military surveillance drone which they claimed to have shot down in Sheikh Meskeen near Deraa, Syria December 15, 2015. Picture taken December 15, 2015. REUTERS/Alaa Al-Faqir 

Subcommittee chair Michael Burgess (R-TX) (R) discusses an Intel AscTec Firefly drone (bottom) with Intel Senior Vice President Josh Walden (C) before a demonstration flight at the House Commerce, Manufacturing and Trade subcommittee on Capitol Hill in Washington November 19, 2015. REUTERS/Gary Cameron

Jan Stumpf of Ascending Technologies holds an Intel AscTec Firefly drone during a flight demonstration at the House Commerce, Manufacturing and Trade subcommittee on Capitol Hill in Washington November 19, 2015. REUTERS/Gary Cameron

An Intel AscTec Firefly drone is seen before a flight demonstration at the House Commerce, Manufacturing and Trade subcommittee on Capitol Hill in Washington November 19, 2015. REUTERS/Gary Cameron

Jan Stumpf of Ascending Technologies controls an Intel AscTec Firefly drone during a flight demonstration at the House Commerce, Manufacturing and Trade subcommittee on Capitol Hill in Washington November 19, 2015. REUTERS/Gary Cameron