A student runs for cover as riot police clash with students during a demonstration on February 29, 2012 in Barcelona, Spain. Student associations have called upon 120,000 students to strike in protest against education cuts recently announced by the Catalan government. (Photo by David Ramos/Getty Images)

Riot police clash with protesters during a rally to demand a referendum to remove Venezuela's President Nicolas Maduro in Caracas, Venezuela, September 1, 2016. (Photo by Marco Bello/Reuters)

Demonstrators confront riot police during clashes in central Brussels November 6, 2014. Tens of thousands of public and private sector workers, employees and trade union members demonstrated over austerity measures to be taken by the new Belgian government. (Photo by Francois Lenoir/Reuters)

A supporter of the opposition parties shouts asking for peace as riot police are block access to the house of the former president Henri Konan Bedie, in Abidjan, Ivory Coast, Tuesday, November 3, 2020. (Photo by Leo Correa/AP Photo)

A demonstrator scuffles with riot police during a rally ahead of International Women's Day, in Ankara, Turkey on March 6, 2022. (Photo by Cagla Gurdogan/Reuters)

An injured demonstrator hugs another as riot police officers prevent them from attending a Pride parade, which was banned by local authorities, in central in Ankara, Turkey on June 29, 2021. (Photo by Cagla Gurdogan/Reuters)

To the woman presented a flower in Sevastopol, Ukraine, on March 8, 2013. Activists presented this day on the street free 155 tulips to women. The police tried to arrest activists for illegal trade as couldn't believe in free distribution of flowers. (Photo by Sergey Anashkevitch)

Jo-Anne McArthur’s book of photographs puts the spotlight on ethics of zoos around the world. Accompanied by essays by Born Free Foundation’s Virginia McKenna and philosopher Lori Gruen, the images and stories are also shared online through “A Year of Captivity”. Here: Asian Elephant, Denmark, 2016. (Photo by Jo-Anne McArthur/Born Free Foundation/The Guardian)