The Wages of Humanity

An assassin has been given a peculiar and bewildering mission: An alliance of the world's richest tycoons is offering an exorbitant price for him to kill the three poorest people on earth. What could have led these billionaires to come up with such a perversely cruel plan? Why would they possibly feel threatened by such ragged, penniless vagabonds? Could it have something to do with the aliens and their occupation?