Graffiti left behind by Taliban fighters remains on the walls of a compound now used as a command center for the U.S Marine Corps's First Battalion, Eighth Marines at Musa Qala in southern Afghanistan's Helmand province, November 10, 2010.Musa Qala is an important battleground in the war against Taliban insurgents and the narcotics industry. The town has changed hands several times, most recently in December 2007 when Afghan and international forces retook the town from the Taliban.

Graffiti left behind by Taliban fighters remains on the walls of a compound now used as a command center for the U.S Marine Corps's First Battalion, Eighth Marines at Musa Qala in southern Afghanistan's Helmand province, November 10, 2010.

Graffiti left behind by Taliban fighters remains on the walls of a compound now used as a command center for the U.S Marine Corps's First Battalion, Eighth Marines at Musa Qala in southern Afghanistan's Helmand province, November 10, 2010.

Graffiti reading "The Few, The Proud," by a previous deployment of the U.S Marine Corps's, adorns the walls at Musa Qala in southern Afghanistan's Helmand province, November 10, 2010.

Layers of graffiti dating back to a previous British deployment mark the walls at Musa Qala district center, now used by U.S. Marines, in southern Afghanistan's Helmand province November 13, 2010.

Graffiti dating back to a previous British deployment marks the walls at Musa Qala district center, now used by U.S. Marines, in southern Afghanistan's Helmand province, November 13, 2010.

Work by Ivorian painter Abdoulaye Diarrasouba, 26, who goes by the name Aboudia, depicts a United Nations vehicle driving past a dead body during recent upheaval in Ivory Coast, at his studio in the main city Abidjan, April 19, 2011.

Work by Ivorian painter Abdoulaye Diarrasouba, 26, who goes by the name Aboudia, depicts recent upheaval in Ivory Coast, at his studio in the main city Abidjan, April 19, 2011. Heavily influenced by the late U.S. artist Jean-Michel Basquiat, Abdoudia continued working on his grafitti-style paintings as fighting raged outside his studio during recent weeks. He was sometimes forced to stop painting when bullets whistled too closely overhead, but he used his fear and worry to create a colourful and often ghoulish record of the violence that gripped the country since contested elections late last year.

Garbage is piled up in front of a caricature of Muammar Gaddafi in the rebel stronghold of Benghazi March 11, 2011. Like many dictators, Gaddafi carefully controlled how his image was used, often portraying himself as a deity or beloved leader. With the rebellion, however, freedom of expression in rebel controlled areas means that ridicule has become a key weapon in the fight against the climate of fear that has long gripped the country. Anti-Gaddafi caricatures and graffiti have sprung up across cities such as Benghazi portraying him in an unflattering light.

A caricature of Muammar Gaddafi is painted on the wall of the garrison headquarters beside a destroyed tank where a major battle took the lives of more than 100 people in the rebel stronghold of Benghazi March 11, 2011.

A girl walks past graffiti on a market wall in Niger's capital Niamey September 11, 2011.

Grafitti adorns a wall in a shared room of an abandoned building that is home to hundreds of foreigners squatting in the Central Business District of Johannesburg, March 3, 2010. South Africa faces a host of challenges related to crime and poverty. Thousands of foreigners, many of them refugees from Zimbabwe, squat in squalid conditions in abandoned downtown buildings.

War-time graffiti adorns the walls of a guest room in a destroyed luxury resort built by the late dictator Mobutu Sese Seko in Virunga National Park and occupied by rebels during the long-running conflict in eastern Congo, August 28, 2010.

A boy leans against a wall with graffiti of a rocket-propelled grenade launcher at a former rebel camp in a rubber plantation, outside the Liberian capital Monrovia, August 27, 2005.

A boy walks past graffiti on a wall on Goree Island off Senegal's capital Dakar, November 3, 2008.

Graffiti adorns a concrete tidal flood barrier along the River Thames in east London, November 24, 2010.

Graffiti adorns a wall in an industrial area on the banks of the Thames River in east London December 15, 2007.