Rather than the infinite choices of fuzzy logic, or the two in binary logic, this would have options for false, true, sort of true, sort of false, and exactly half-way.
By sending an email that repels all but the most gullible the scammer gets the most promising marks to self-select, and tilts the true to false positive ratio in his favor.
"The notion of a 'graveyard of empires' is actually a false extrapolation from something that is true -- that there is tactical and strategic difficulty, " Porter says.