At the NY Area Theory Day, I started my talk with a story. When I was 10 years old, I played this game where the other party will repeatedly toss a coin, and I would predict the outcome each time. I developed a trick to predict correctly significantly more than 50% of the times. I told the trick to the audience and lost many of them who spent the rest of the talk wondering or disagreeing that it would work. Graham Cormode pointed out that besides the trick, the challenge is to pull it off since it required some worldly social skills.
I was reminded of this when I read about a scam in India. Roughly, via email solicitation, for a fee, someone delivers a trunk full of blackened currency to you. And then asks you for money to send you chemicals that will clean and resurrect the bills. Of course the bills turn out to be bogus. This scam
seemed silly. I would have liked to see one in which you get delivered the trunk full of blackened currency free of charge, then you are asked to pay a small amount and get delivered a small quantity of chemicals that cleans and retrieves a few genuine or high quality bogus currency bill, and finally the victim gets hit for a larger batch, producing only counterfeit or bogus notes. No, I am not recommending such a scheme, just pointing out that the scheme could be made more nuanced.