" Once the groups are on their feet, they are perfectly capable of raising funds through other means, like; kidnapping, oil smuggling, selling women into slavery… According to intelligence official; any outside funding represents a small fraction of ISIS's total annual income… The largest source of cash now is oil smuggling along the Turkish border, with ISIS leaders willing to sell oil for as little as $25 a barrel, a quarter of the going world price. Since other previously lucrative sources, such as; kidnapping for ransom… is not as profitable as it once was."
Scratches to Sketches