How about coins with privacy tagged? They run a full private anonymity with coin without showing any track back of sender from a certain transaction. The decentralized approach make them anonymous already, unless you've enter a centralized exchange that has fiat option, normally this will have a KYC process that could lesd youre personal info known, so those criminals are still preferred dex. But IDEX, show some improvement since they need verification now, maybe due to this.