The big thing about it is that it is untraceable. I read about it before. Can't remember exactly how it is done, but the coins are used to purchase illegal things and keep the buyer anonymous from authorities.
Just because they tell you there's no record, doesn't mean there's no record. Look at it like this. Even France knows how to spy on its own people, so you better be sure some guy who sells you stuff that makes you anonymous knows how to keep records.