system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: We keep hearing that ISIS has millions of dollars in revenue, but where does it keep this money and why is it so difficult to cut off the money?
gpt
They are getting it from oil illegally transported out of their borders, "taxes" on the people inside their borders, extortion, hostage exchanges, all the normal ways large organizations get money illegally. We can't stop oil exports because we don't have the resources to clamp down all of their borders, we can't stop taxation or extortion because they have the power in those areas, and we can't stop hostage taking because people keep going to the region. It's a mess.