An activist of the anti-G8 forum “Block G8” shows his middle finger to a police helicopter passing overhead June 07, 2007 at Bollhagen, near Heiligendamm, Germany. (Photo by Carsten Koall/Getty Images)

Chinese special policemen rank in a line of battle during an anti-terror drill at a training base of Chengdu Armed Police Headquarters on September 28, 2005 in Chengdu of Sichuan Province, China. (Photo by China Photos/Getty Images)

Paint splattered police officers look on during clashes outside Top Shop on Oxford Street, during marches in protest at government cuts on March 26, 2011 in London, England. Thousands are taking part in the Trades Union Congress (TUC) organised march to Hyde Park where a rally will take place. Police say they are deploying 4500 officers. (Photo by Dan Kitwood/Getty Images)

Mamoni Mandal, member of the Rapid Action Force (RAF), attends a training session at a police training school in Kolkata April 15, 2007. (Photo by Parth Sanyal/Reuters)

Riot police runs as a woman falls down during a May Day rally in the Kreuzberg district of Berlin, Germany, 01 May 2016. (Photo by Kay Nietfeld/EPA)

Brian Anderson has been taking images of Glasgow for 20 years, spotlighting both the light and dark side of life. Brian, 40, said: “Glasgow is full of character. It’s a nice city, it’s a crazy city and I want to show all that”. Photo: Police look on as a man tries to break up brawling women in Queen Street. (Photo by Brian Anderson)

Protesters take part in “Artists Take Fight Against Police Murders” in New York's Times Square August 13, 2015. (Photo by Brendan McDermid/Reuters)

A Swiss police officer accompanies a migrant from Syria carrying her baby, upon her arrival at the railway station in the north-eastern Swiss town of Buchs September 1, 2015. (Photo by Arnd Wiegmann/Reuters)