In a secret project tied to the overall U.S. campaign against the Islamic State, intelligence officials have spent months mapping out known physical locations of media safe houses where the extremist group’s operatives are compiling, editing and curating raw video and print materials into finished digital propaganda products for dissemination across the Internet. Most of the locations are embedded in heavily residential areas in Syria, Iraq and Libya and are not being targeted by U.S. airstrikes because of Obama administration concerns about civilian casualties, according to sources who spoke to The Washington Times only on the condition of anonymity.