Sure. Specifically with reference to the Islamic State, it's probably important to point out how this happens. It's not necessarily a case of guys from ISIS going out and digging and looting artifacts and sculptures that they find themselves. What you have is a phenomenon such that they have control of an area, they control the territory, and they pretty much allow the locals to dig, and they tax the proceeds. Getting back to the idea of just taxing whatever is sold, it's sort of an open environment. They don't necessarily pillage themselves, but they're in these areas where you have millennia's worth of artifacts that can be found and they just allow people to find them or bring them and sell them. When they're sold, they get a share of the proceeds.
That's the layout. That's how it happens.
You mentioned the underground economy, which I think we don't really understand. We don't have the same sort of attention to this economy.
Actually a few weeks ago, I read an article, not about ISIS but about a historic Italian book, I think maybe from the Renaissance period, that was found. It was sold by an art dealer. The U.S. Homeland Security had a team that went in and did all the digging and recovered the book, and the book was at a library at Johns Hopkins University.
I talked to the people at Johns Hopkins and they said that for artifacts there's really no process like the Kimberley process for blood diamonds, under which items have to go through a very strict certification to verify that they are not from illicit trade.
There are safeguards, but they're not that rigorous. There's a lack there.