This makes me think of those stories like the movie 20 Bucks that were popular for a while... someone takes a $20 out of an ATM machine (which were new and exotic at the time) and the story unfolds as the camera follows the money. With a central bank holding the keys to the crypto chain, they also get to see how money moves in both legitimate and illegal ways... and then get to make judgments on the entire chain of custody. What do they do with the information that the $20 bill was used by a hooker to snort coke, before being given to a convenience store clerk, who then gives it as change to a soccer mom? These links are ripe for misuse by any government agency. An auditable record of every transaction makes me a little nervous (probably in an "old man yells at cloud" kind of way, honestly), but it'd be nice for the BoE to just adopt a useful tech like ETH and move on. We can dream...