A sign near a checkpoint of a vigilante group reads Civilian J.T.F or Civilian Joint Task Force on July 19, 2013 in Maiduguri, where Boko Haram has carried out most of its deadly attacks in a four-year insurgency that has left some 3,600 people dead since 2009, according to Human Rights Watch. Young men and women have in recent weeks formed vigilante groups, hunting down Boko Haram Islamists who have sneaked back into the city following a military offensive on their camps on the Nigerian border with Niger, Chad and Cameroon with remarkable success. AFP PHOTO / Aminu ABUBAKAR (Photo credit should read AMINU ABUBAKAR/AFP/Getty Images)
