 By using instant payment mechanisms such as Western Union, the mule allows the thief to transform a reversible and traceable transaction into an irreversible and untraceable one.If an innocent third party's bank details have been compromised, they can be used as a mule without their knowledge, something sometimes called "cookoo smurfing".Criminals trading in stolen or illegally acquired goods use similar tactics to recruit mules who receive packages and forward them to mail drops not traceable to the criminal.