Street fighting in Berlin between Government troops and Spartacists, during the Spartacist uprising which followed Germany's defeat in World War I. (Photo by Keystone/Getty Images). 1919

Christina Careaga (R) and Hannah Thielmann kiss as they celebrate during the Gay Pride parade on June 26, 2011 in New York City. The parade took on extra significance following Friday night's legalization of same-s*x marriage in New York, often regarded as the birthplace of the gay rights movement. (Photo by Mario Tama/Getty Images)

Egyptian President Hosni Mubarak speaks to the media after talks with German Chancellor Angela Merkel at the Chancellery on April 23, 2008 in Berlin, Germany. (Photo by Sean Gallup/Getty Images)

A young exhibitor arrives with her kitten on a lead at the National Cat Club show at Crystal Palace, London. (Photo by Fox Photos/Getty Images). 2nd December 1931

Doris Pennman adjusts her umbrella as she walks along Mission Beach on January 8, 2005 in San Diego, Califonia. (Photo by Sandy Huffaker/Getty Images)

Sheep are herded during the annual sheep parade through Madrid November 2, 2014. Shepherds parade the sheep through the city every year in order to exercise their right to use traditional routes to migrate their livestock from northern Spain to winter grazing pasture land in southern Spain. (Photo by Susana Vera/Reuters)

It’s time to start watching for Comet PANSTARRS, one of two comets to get excited about in 2013. Photo: This image provided by NASA shoaws the comet PANSTARRS as seen from Mount Dale, Western Australia on March 5, 2013. According to NASA on March 10, it will make its closest approach to the sun about 28 million miles (45 million kilometers) away. As it continues its nightly trek across the sky, the comet may get lost in the sun's glare but should return and be visible to the naked eye by March 12. (Photo by AP Photo/NASA)

Kent Josephso organizes his 8mm tracer rounds during the Big Sandy Shoot in Mohave County, Arizona March 23, 2013. The Big Sandy Shoot is the largest organized machine gun shoot in the United States attended by shooters from around the country. Vintage and replica style machine guns and cannons are some of the weapons displayed during the event. Picture taken March 22, 2013. (Photo by Joshua Lott/Reuters)