Only as you say if you convert them into a "real" currency. If they only used their Bitcoin to purchase goods (such as VPS) which was not tied to a physical add

Only as you say if you convert them into a "real" currency. If they only used their Bitcoin to purchase goods (such as VPS) which was not tied to a physical address, then they could still remain anonymous. As for where the Bitcoins came from, I'm sure the author of this document would have some digital assets they could sell on the darknet to acquire some Bitcoin. Where those Bitcoin originated then would not be their problem.