Protestors throw stones over the steel security barriers around the National Congress, where the swearing in of new Mexican President Enrique Pena Nieto is taking place in Mexico City, Saturday, Dec. 1, 2012. (AP Photo/Eduardo Verdugo)

Photo by: Eduardo Verdugo

Protestors throw stones over the steel security barriers around the National Congress, where the swearing in of new Mexican President Enrique Pena Nieto is taking place in Mexico City, Saturday, Dec. 1, 2012. (AP Photo/Eduardo Verdugo)