Police walk past a burning car during riots in Birmingham City Centre on August 8, 2011 in Birmingham, England. After three nights of rioting and looting in and around London, the chaos is starting to spread to other cities around Britain. (Photo by Jeff J Mitchell/Getty Images)

In a July 14, 1967 file photo, left, National Guardsmen make their way along Market Street in Newark, N.J, after an evening of deadly rioting and looting in what came to be known as the Newark riots. In a June 16, 2017 photo, right, an ambulance drives on the same block 50 years later. (Photo by AP Photo/File, left; Julio Cortez, right)

Farmers clash with riot policemen during a protest outside the Greek Agriculture Ministry on March 8, 2017 in Athens, Greece. Two people were detained after the windows of two police vans were smashed as approximately 1,000 farmers, mainly from the island of Crete, took part in the protest. (Photo by Nikolas Georgiou/ZUMA Wire/Rex Features/Shutterstock)

A woman protests her eviction from a building she and others invaded about a week ago in the Flamengo neighborhood of Rio de Janeiro, Brazil, Tuesday, April 14, 2015. Police dislodged squatters from the building slated for use as a luxury hotel for the 2016 Olympics in Rio de Janeiro. (Photo by Silvia Izquierdo/AP Photo)

In this photo taken Tuesday, April 14, 2015, immigrant men armed with machetes make their way onto a Durban, South Africa, street during clashes with police and in search of locals that attacked foreign shop owners in the city center. (Photo by Tebogo Letsie/AP Photo)

“On Friday, after something of a show trial, three young women in a Russian punk band were found guilty and sentenced to two years in prison for an anti-Vladimir Putin protest in a Moscow cathedral earlier this year”. – Daniel Schwartz via CBC News

Photo: A woman wears on her chest the text “free p*ssy riot” as a demonstration by supporters of the jailed feminist punk band p*ssy Riot takes place outside the Russian Embassy on August 17, 2012 in London, England. The three women who staged an anti-Kremlin protest in a church in February, were found guilty today of hooliganism motivated by religious hatred, and could face a three-year jail sentence. Supporters are gathering in several cities around the world today as a mark of solidarity. (Photo by Dan Kitwood)

Metropolitan Police officers prepare to carry out a raid on a property on the Churchill Gardens estate in Pimlico during Operation Woodstock on August 11, 2011 in London, England. Over 1,000 people have been arrested since the rioting began on Saturday and Police have started to raid properties across the capital as they round up people suspected of involvement in the rioting and recover stolen property. (Photo by Anthony Devlin - WPA Pool/Getty Images)

Members of the public continue to pay their respects at the scene of a hit and run following civil disturbances in the Winson Green area on August 12, 2011 in Birmingham, England. Police are continuing investigations after three people – reportedly trying to protect shops from rioting and looting in Dudley Road – were struck by a car and killed during rioting. Police have so far arrested over 1,000 people following rioting which erupted over a four-day period across the UK. (Photo by Jeff J Mitchell/Getty Images)