Quentin Somerville, BBC News, and his colleagues have a photo-essay 'The Secret Lives of IS Fighters', sub-titled: 'Three young IS militants lie dead on the banks of the River Tigris. They left behind personal photos and documents which reveal the extraordinary story of their private lives.'
Link:http://www.bbc.co.uk/news/resources/idt-sh/is_fighters

Some points to note, including an Iraqi infiltrator in IS.