A Brazilian drug gang member nicknamed Pilintra, 26, poses with a gun atop a hill overlooking a slum in Salvador, Bahia State, April 11, 2013. One of Brazil's main tourist destinations and a 2014 World Cup host city, Salvador suffers from an unprecedented wave of violence with an increase of over 250% in the murder rate, according to the Brazilian Center for Latin American Studies (CEBELA). (Photo by Lunae Parracho/Reuters)

Londoners enjoy a “Silent Night” as Big Ben falls silent, London, UK on August 21, 2017. ose Allerston from Clapham, London said “After a stressful day in the office, I couldn't think of anything better than going home and climbing into bed – but when I saw this bed opposite Big Ben I just couldn't resist getting in for a snuggle”. (Photo by Imagewise Ltd/Rex Features/Shutterstock)

A protester is sprayed with mace by riot police after throwing a chair through a window of a business during the second night of demonstrations after a not guilty verdict in the murder trial of former St. Louis police officer Jason Stockley, charged with the 2011 shooting of Anthony Lamar Smith, who was black, in St. Louis, Missouri, U.S., September 16, 2017. (Photo by Lawrence Bryant/Reuters)

A Boeing 777-300 from Swiss International Airlines lands on a foggy morning at Zurich Airport, on Friday, October 13, 2017, in Zurich, Switzerland. The high humidity renders the air vortex visible. (Photo by Christian Merz/Keystone via AP Photo)

Bride Katty Malang Mikunug with friends, takes a photo before the wedding on October 21, 2017 in Saguiaran in Lanao del Sur, southern Philippines. Paulo Mamayo Ambor, 22, a resident of Marawi who got displaced by the fighting between government troops and IS-inspired militants, weds Katty Malang Mikunug, 22, a resident of an adjacent town in Saguiaran. Philippines President Rodrigo Duterte declared Marawi liberated, following the death of Abu Sayyaf leader Isnilon Hapilon and one of the Maute brothers, Omar Maute, after nearly five months of fierce urban battle inside the besieged city. The fighting started May 23, and left more than 1,000 people dead, whilst displacing at least 400,000 people. (Photo by Jes Aznar/Getty Images)

Villagers offer flowers to a wild tusker, laying dead in a field in Panbari villagein Panbari village on the outskirts of Gauhati, India, Thursday, November 2, 2017. According to a veterinarian the tusker died of food poisoning. Scarcity of food and illegal encroachment of forest areas have forced these wild elephant to move to populated areas for food. (Photo by Anupam Nath/AP Photo)

Tactics reminiscent of the early American frontier days are now being used in Vietnam. Lieutenant Commander Donald D. Sheppard, UBN, of Coronado, California, aims a flaming arrow at a bamboo hut concealing a fortified Viet Cong bunker on the banks of the Bassac River, Vietnam on December 8, 1967. (Photo by AP Photo)

A Pakistani vendor prepares peanuts for sale on a roadside in Peshawar, Pakistan, 01 January 2018. After a good raining season the sales of dry fruits flourish in the country. Tourists from all over Pakistan come to Peshawar to purchase dry fruits along with other items because of price differences between different parts of the country. (Photo by Bilawal Arbab/EPA/EFE)