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)

Participants of an unauthorized opposition rally gather in Tverskaya street in central Moscow on June 12, 2017. Authorities detained Russian opposition politician Alexei Navalny and hundreds of his supporters on Monday, as they mounted demonstrations across the nation against government corruption. Over 200 were detained in Moscow and Saint Petersburg an hour into the protest, according to an NGO that tracks arrests, with Navalny himself picked up by police in his building as he was headed to the event. (Photo by Vasily Maximov/AFP Photo)

A fan of Serbia scuffles with Albania's Mergim Mavraj during their Euro 2016 Group I qualifying soccer match at the FK Partizan stadium in Belgrade October 14, 2014. The Euro 2016 qualifier between Serbia and Albania was abandoned on Tuesday following a brawl between players from both sides. (Photo by Marko Djurica/Reuters)

This photo provided by NASA astronaut Christina Koch shows the launch of a Russian Soyuz rocket, as seen from the International Space Station on Wednesday, September 25, 2019. (Photo by Christina Koch/NASA via AP Photo)

Relatives gather to identify bodies in the village of Nyamukubi, South Kivu province, Congo, Saturday, May 6, 2023. The death toll from flash floods and landslides in eastern Congo has risen to over 150, with some 100 people still missing, according to a provisional assessment given by the governor and authorities in the country's South Kivu province. (Photo by Moses Sawasawa/AP Photo)

Filipino informal settlers react during a demolition raid at a shanty town in Pasay City, Metro Manila, Philippines, 01 August 2024. (Photo by Francis R. Malasig/EPA)

Supporters react as U.S. President Donald Trump walks from Marine One to the White House in Washington, U.S., October 3, 2019. (Photo by Tom Brenner/Reuters)

Drag guests attend RuPaul's DragCon UK presented by World Of Wonder at Olympia London on January 19, 2020 in London, England. (Photo by Tristan Fewings/Getty Images for World Of Wonder Productions)