Hanging from the balls is a vulgar, popular expression with which someone desires or manifests a bad punch to a male human being for his actions. It is a metaphor or eupheistic expression. Balls is metaphor, by similarity, with the testicles of males. So its real meaning is to hang, by rope or cable, someone by their parts, rather than by the neck. It underlines the fact of his evil, by making him dependent on cause and effect : being hung from his sex, he denotes that this was his sin. The saying is fulfilled : In sin, he carries penance.