 In 2006 , Bono recounted another experience he had in El Salvador , where he had seen a body thrown from a van into the road . He remarked , " People would just disappear . If you were part of the opposition , you might find an <unk> with the windows <unk> out parked outside your house .... If that didn 't stop you , occasionally they would come in and take you and murder you ; there would be no trial . " Bono understood the cause of the Madres and COMADRES and wanted to pay tribute to it . His experiences in Central America inspired the lyrics of " Mothers of the Disappeared " and another track from The Joshua Tree , " Bullet the Blue Sky " . 
