And who is buying from the black-market traders?
Kinda hard to hide all that oil, it’s gotta be going somewhere, who needs to buy on the black market?
The way I read it is, the black market smuggling has been going on for a long time. Dictators like Assad and Saddam Hussein probably liked keeping some of the oil production off the books, in order to get around OPEC, to have a slush fund, to pay off cronies, etc. It's not like the oil was being audited by PriceWaterhouse!
And on the Turkey connection, there's also corruption and a desire not to have a true set of books regarding oil. I'm sure they have a lot of ways to falsify where the oil is coming from, and a lot of gov't officials getting paid off.
So this black market stuff has been going on a long time and has developed an infrastructure and camouflage. The change with ISIS being involved is, ALL the oil now has to go through the black market channel, so there may be an increase in the illicit volume, but since total oil production is way down in the ISIS areas, that may not be a big change.
It looks to me like it would be tough to find out who's trading and buying the oil.