Rival supporters taunt each other after the FA Cup Third Round match between Manchester City and Manchester United at the Etihad Stadium on January 8, 2012 in Manchester, England. Localised clashes and stone throwing between fans took place on the streets after Manchester United beat Manchester City 3–2. (Photo by Christopher Furlong/Getty Images)

Visitors to Castle Combe take photographs in the village that was recently featured in Steven Spielberg's latest film, the wartime drama, War Horse, on January 10, 2012 near Chippenham, England. (Photo by Matt Cardy/Getty Images)

In this April 28, 2014 file photo, a woman throws a rock and a bag at police blocking her from getting home in the Huepetuhe district of the Madre de Dios region of Peru. Security forces began destroying illegal gold mining machinery in Peru's southeastern jungle region of Madre de Dios, as authorities began enforcing a ban on illegal mining. (Photo by Rodrigo Abd/AP Photo)

A lioness bares its teeth inside an enclosure after a raid at a zoo-like house on the outskirts of Bangkok, Thailand Monday, June 10, 2013. Thai police and forestry officials searched and seized a number of imported and endangered animals including 14 lions from Africa and arrested the house's owner. (Photo by Apichart Weerawong/AP Photo)

Waves crash over lava as it flows into the ocean near Volcanoes National Park in Kalapana, Hawaii on November 27, 2012. A volcano on Hawaii's largest island is spilling lava into the ocean, creating a rare and spectacular fusion of steam and waves that officials said on Tuesday could attract thrill seeking visitors if it continues. (Photo by Hugh Gentry/Reuters)

One of two 9-month old Cheetahs is seen after it was released into a quarantine facility at Zoo Miami on November 29, 2012 in Miami, Florida. The two sub-adult brothers who arrived today were captive-born on March 6th of this year at the Ann van Dyk Cheetah Centre just outside of Pretoria, South Africa. The Cheetahs, after being monitored and examined for a minimum of 30 days to insure that they are healthy and stable, will be featured in Zoo Miami's Wildlife Show at the newly constructed amphitheater and will continue the work of Zoo Miami's Cheetah Ambassador Program by making appearances off Zoo grounds at a variety of venues including schools and civic organizations. (Photo by Joe Raedle)

U.S. Army soldiers from the 2-82 Field Artillery, 3rd Brigade, 1st Cavalry Division, wait to load onto their armored vehicles as they prepare to convoy to Kuwait from Camp Adder in Iraq on December 7, 2011 at Camp Adder, near Nasiriyah, Iraq. (Photo by Joe Raedle/Getty Images)