Actress Salma Hayek holds up a sign reading “bring back our girls”, part of a campaign calling for the release of nearly 300 abducted Nigerian schoolgirls being held by Nigerian Islamic extremist group Boko Haram, as she arrives for the screening of Saint-Laurent at the 67th international film festival, Cannes, southern France, Saturday, May 17, 2014. (AP Photo/Thibault Camus)