An Armatix employee holds a “smart gun” by the company at the Armatix headquarters in Munich May 14, 2014. The gun is implanted with an electronic chip that allows it to be fired only if the shooter is wearing a watch that communicates with it through a radio signal. If the gun is moved more than 10 inches (25 cm) from the watch, it will not fire. A Maryland gun shop owner has dropped his plan to be the first in the United States to sell the so-called “smart gun” after a backlash that included death threats. (Photo by Michael Dalder/Reuters)

Actors dressed as a “Yeti” attend a promotional event for Travel Channel's “Expedition Unknown: Hunt for the Yeti” in Manhattan, New York City, U.S., October 4, 2016. (Photo by Brendan McDermid/Reuters)

A man sleeps on a wheelbarrow outside a closed shop at a market during the first day of a ceasefire in Yemen's capital Sanaa April 11, 2016. (Photo by Khaled Abdullah/Reuters)

An Extinction Rebellion environmental activist couple getting married at an action site they are calling “The Beacon” on Westminster Bridge on October 7, 2019 in London, England. Primarily made up of London based activists the site is one of 12 situated around key Government locations in central London as actions are also predicted to occur in unto 70 cities around the world. The group aim to occupy the areas in central London for up to two weeks through non violent protest with an estimated 8 times as many people as their April protests which saw over 1,200 people arrested. (Photo by Ollie Millington/Getty Images)

A U.S. army soldier exercises in front of a M270A1 multiple launch rocket system as they prepare for a live-fire training exercise of the 6-37th Field Artillery Regiment at a training area near the demilitarized zone separating the two Koreas, in Cheorwon, South Korea, March 9, 2016. (Photo by Kim Hong-Ji/Reuters)

The US Navy Blue Angels numbers 5 and 6 fly below Sean Tucker (above) as he pilots the Oracle Challenger III over San Francisco, California as part of a practice run for Fleet Week on October 6, 2016. (Photo by Josh Edelson/AFP Photo)

People walk past a New Year fir tree made of toys at a park in Krasnoyarsk, Siberia, Russia January 2, 2017. (Photo by Ilya Naymushin/Reuters)

A racegoer is given some water as he lays on the ground following 2017 Stakes Day at Flemington Racecourse on November 11, 2017 in Melbourne, Australia. (Photo by Scott Barbour/Getty Images)