SAN SALVADOR, EL SALVADOR - MAY 20:  An MS-13 gang members gestures the Devils Head insignia inside one of the three 'gang cages' in the Quezaltepeque police station May 20, 2013 in San Salvador, El Salvador. These overcrowded, 12x15 cages were designed to be 72-hour holding cells for common criminals and the two rival gangs, but many of the individuals have been imprisoned for over a year.  (Photo by Giles Clarke/Getty Images.)