Nigerian letters: the Russian Doll scam
Russian dolls come in a nested set. You open one, and find another, smaller doll within. And so on, and so forth. Nigerian letters are by now so commonplace that any Internet user likely has already received several. Therefore, it is getting really tough for crooks writing these letters to get money out of them. Some years ago, they started variants of a scam-within-scam (see one example here), purporting to offer UN compensation to victims of Nigerian letters. There is of course no need to explain that the real purpose of this letter is to scam you a second time (in this specific case, requesting "advance fees" for the processing of your compensation claim, and continuing to request money until you get tired of paying).
There is now a scam-within-scam-within-scam variant. Since everybody by now knows, or guesses, that there are no UN compensation funds for victims of Nigerian letter scams, the new variant "explains" that earlier requests for compensation were sent to the wrong person/organization, and gives you the identity of the "real" person who will issue a generous refund for money lost through your earlier naivety (so generous, in fact, that you do not need to give any proof of having lost money to earlier scams). The scam then proceeds to ask for "advance fees" as usual, and so on, and so forth. If you should be so naive and/or desperate as to travel to Nigeria in order to meet the fabled priest described in this letter, you will put yourself literally in the hands of criminal gangs legendary for their brutality and ruthlessness, impunely operating in one of the most corrupt societies in the world.
Among tried and tested, recurrent themes in Nigerian letters, notice the fact that the persona writing the letter is a dignified woman (and thereby less threatening according to popular wisdom) and the persona answering her compensation claim is a honest priest (also less likely to be a crook in unsuspecting eyes). Try to imagine instead a gun-toting fat guy sitting in a bare room in his underwear and guzzling palm wine from a plastic tank while typing on a laptop, and your mental image is probably closer to the truth.
Here is the letter from "the most happiest woman on earth". I omit the headers, since they are only of technical interest.
Another variant of the "scam within scam" is an unsolicited offer to provide you with a large financial loan at below-market interest rate, no questions asked. "Why not?" you might be tempted to think. After all, they are the ones who take a risk by lending me their money. Specifically, you might be tempted by the thought of being able to scam them out of their loan money. As always, there is no money waiting for you behind the corner, only an endless series of request for fees and bribes before you can partake of your non-existent loan.