Flavio SosaAnchor Lisa Mullins speaks with The World's Franc Contreras about the arrest of a leftist activist in Mexico. The activist has spear-headed months of street protests in the southern Mexican city of Oaxaca. His arrest comes in the first week in office for Mexico's new president, Felipe Calderon. Photo: The leader of a protest movement in Oaxaca state, is now in custody in a maximum security prison just outside Mexico City.