Serbian police officers of the Special Anti-Terrorist Unit pose for a picture in their base outside Belgrade October 8, 2014. When the killing of an unarmed black teenager by a white policeman in Ferguson, Missouri, in August sparked sometimes violent protests, the response of police in camouflage gear and armoured vehicles wielding stun grenades and assault rifles seemed more like a combat operation than a public order measure. Some U.S. police departments have recently acquired U.S. military-surplus hardware from wars abroad, but there are many law enforcers around the world whose rules of engagement also allow the use of lethal force with relatively few restrictions. But for every regulation that gives police wide scope to use firearms, there is another code that sharply limits their use. In Serbia, police may use measures ranging from batons to special vehicles, water cannon and tear gas on groups of people who have gathered illegally and are behaving in a way that is violent or could cause violence, but they may use firearms only when life is endangered. (Photo by Marko Djurica/Reuters)

Mayu adjusts Koiku’s kimono, as Koiku wears a protective face mask while posing for a photograph, before they work at a party where they will entertain with other geisha at Japanese luxury restaurant Asada in Tokyo, Japan, June 23, 2020. (Photo by Kim Kyung-Hoon/Reuters)

Chinese women wear protective masks as they are dressed in traditional clothing from the Qing Dynasty era outside a park on March 29, 2020 in Beijing, China. A limited section of the iconic tourist site was re-opened to the public this week allowing a smaller number of visitors to reserve tickets online in advance and to enter after passing health screening. (Photo by Kevin Frayer/Getty Images)

A protester runs from a jet of water shot from a police water cannon in the courtyard of the University of Santiago, during clashes between students and police, in Santiago, Chile, Thursday, May 14, 2015. In the capital and other cities across the country, high school and university students marched, for the second time this year, to demand education reform. (Photo by Luis Hidalgo/AP Photo)

“The Lockheed Martin X-33 is an unmanned, sub-scale technology demonstrator suborbital spaceplane developed in the 1990s under the U.S. government-funded Space Launch Initiative program”. – Wikipedia

Photo: An Artist's Rendering Shows How Nasa's X-33 Technology Demonstrator, A Cost-Cutting Fully Reusable Single-Stage-To-Orbit Space Vehicle, Will Look Upon Completion. The 67 Foot-Long, 278,600 Pound, Twin Engine Space Vehicle, Capable Of Reaching Speeds In Excess Of Mach 15, Will Lead To The Construction Of A 127 Foot-Long, 2,186,000 Pound Version With Seven Engines And A 50,000 Pound Payload Capacity Called The “Venturestar”. (Photo By Nasa/Getty Images)

A woman strikes a police truck with her hand during a protest march in Santiago, Chile, Thursday, April 16, 2015. Thousands of students marched through the streets of Chile's capital to protest recent corruption scandals and to complain about delays in a promised education overhaul. While it was largely peaceful, violence broke out at the end when hooded protesters threw rocks and gasoline bombs at police. (Photo by Luis Hidalgo/AP Photo)