Gunfire erupted at a Denver pot celebration Saturday, injuring two people and scattering a crowd of thousands who had gathered for the first 4/20 counterculture holiday since the state legalized marijuana... Photo: A woman smokes a large marijuana joint at the Vancouver Art Gallery during the annual 4/20 day, which promotes the use of marijuana, in Vancouver, British Columbia April 20, 2013. (Photo by Ben Nelms/Reuters)

A demonstrator is carried during a rally in support of a identity check draft law and against delinquency, in Santiago, Chile April 30, 2016. (Photo by Carlos Vera/Reuters)

Drastic inequality is by no means new in New York. Jacob A. Riis was called a muckraker after he chose to spotlight the city’s poverty at the turn of the 20th century by photographing it. Here: Sweatshop in Hester Street, 1889-1890. (Photo by Jacob A. Riis/Museum of the City of New York, Gift of Roger William Riis)

Kim Leuenberger is a Swiss photographer with a love for travel. She believes we are all explorers and is currently studying photography at University of the Arts London. These photos are from her series, “Traveling Cars Adventures”. Photo: “Lover of the Light”, Red Union Jack Mini Cooper, Bern, Switzerland, October 2012. (Photo by Kim Leuenberger)

An Afghan man works at a traditional yarn factory in Heart province, Afghanistan July 28, 2015. (Photo by Mohammad Shoib/Reuters)

A Muslim woman gets caned 23 strokes after being caught in close proximity with her boyfriend in Banda Aceh on October 17, 2016. Out of seven couples caught spending time together outside marriage, 13 were caned while one girl was spared after it was discovered that she was pregnant. Indonesia's Aceh province has gained international infamy for its strict Islamic laws. (Photo by Chaideer Mahyuddin/AFP Photo)

A young woman holds her smartphone at Red Square with the Kremlin's Spasskaya Tower, right, and St. Basil Cathedral, center, in the background in Moscow, Russia, Monday, July 25, 2016. (Photo by Pavel Golovkin/AP Photo)

A Palestinian woman takes a picture of a member of the Israeli security forces as he takes her picture in a street in Jerusalem on December 16, 2017, as demonstrations continue to flare in the Middle East and elsewhere over the US president' s declaration of Jerusalem as Israel' s capital. (Photo by Ahmad Gharabli/AFP Photo)