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)

Construction cranes stand on the Unstrut Valley high-speed railway bridge on March 19, 2012 near Karsdorf, Germany. The Unstrut bridge, which is 2,668m long (about 1.6 miles), is among 38 bridges and 26 tunnels German state rail carrier Deutsche Bahn is building along a new ICE high-speed railroad connection between Nuremberg, Erfurt, Halle, Leipzig and Berlin in a multi-billion Euro project across eastern Germany called the German Unity Transportation Project (Verkehrsprojekt der Deutschen Einheit). (Photo by Sean Gallup/Getty Images)

Prince Charles, Prince of Wales (R) and Camilla, Duchess of Cornwall (L) visit Seppeltsfield Winery in Barossa Valley, Australia, 10 November 2015. The royal couple are on a 12-day tour visiting seven regions in New Zealand and three states and one territory in Australia. (Photo by Daniel Kalisz/EPA)

Firefighters are seen through heat from flames as they battle the Apple fire near Banning, California on August 1, 2020. 4,125 acres have burn in Cherry Valley, about 2,000 people have received evacuation orders in the afternoon of August 1. Around 8PM the fire spread to 12,000 acres. (Photo by Josh Edelson/AFP Photo)

The Tibetan night sky was captured in these beautiful images showing the stunning buildings and statues in the Himalayan mountains. Grey Chow, 33, traveled for two hours to get to the Spiti Valley to capture the starry backdrop along the isolated, deserted roads. The senior project engineer was able to take amazingly clear images thanks to the limited amount of pollution at the 4,500-foot (1371m) altitude. (Photo by Grey Chow/Caters News Agency)

NHRA top fuel driver Spencer Massey explodes the engine of his dragster on fire during the Thunder Valley Nationals at Bristol Dragway on October 17, 2021. Massey was unhurt in the incident. (Photo by Mark J. Rebilas/USA TODAY Sports)

Charlize Theron attends the 33rd American Cinematheque Award Presentation Honoring Charlize Theron and The 5th Annual Sid Grauman Award Presented by Hill Valley to Adam Aron on behalf of AMC Theatres at The Beverly Hilton Hotel on November 08, 2019 in Beverly Hills, California. (Photo by Michael Buckner/Variety/Rex Features/Shutterstock)