Yemeni men walk past a mural depicting a US drone and a dove in a yin-yang symbol on December 13, 2013 in the capital Sanaa. A drone strike on a wedding convoy in Yemen killed 17 people, mostly civilians, medical and security sources said, adding grist to mounting criticism of the US drone war.  AFP PHOTO/ MOHAMMED HUWAIS        (Photo credit should read MOHAMMED HUWAIS/AFP/Getty Images)