I think you&#x27;re looking for &quot;Why Do Nigerian Scammers Say They are From Nigeria?&quot; by Microsoft Research.<p><a href="http:&#x2F;&#x2F;research.microsoft.com&#x2F;apps&#x2F;pubs&#x2F;default.aspx?id=167713" rel="nofollow">http:&#x2F;&#x2F;research.microsoft.com&#x2F;apps&#x2F;pubs&#x2F;default.aspx?id=1677...</a><p>Edit: Here&#x27;s a particularly illuminating quote: &quot;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.&quot;