Once upon a time in Dulmen...
A curious case took place in Dulmen, Germany. Forty-one-year-old man (let call him Hans) was strolling along the beach together with his wife, and in order not to look into her eyes as if he had something to hide, he was peering at sand under his feet.
After a little he dropped on Euro 30 banknote (which is actually doesn't exist). After logical inferences Hans came to the conclusion that it was fake and put it into his pocket as a keepsake. But a short time afterwards our action man felt like having a cigarette. So he made a dive into a cigarette shop and bought a pack of cigarettes paying with that Euro 30 banknote (that was purely accidental according to him). Salesman didn't notice anything out of line and simply gave the change to Hans along with his pack of cigarettes.
It could have been the end of the story but one day Hans saw the news about his banknote and the sad face of the salesman. Being a man of good morals Hans came to the police station to give himself up saying that that was a mistake and he didn't wish to do it.
The only thing the policeman did was waggling his finger and asking not to do such stuff anymore...