Once upon a time, John D. Rockefeller declared war on the hookworms of Panama. He sent doctors and medicines to his workers there; they soon eradicated the hemophagic parasites.
Rockefeller then declared war on the vampires of Transylvania. He sent crosses and garlic and wooden stakes to his workers there; they soon dispatched the undead bloodsuckers.
As a result, Rockefeller’s workers in Panama and Transylvania had less anemia than before, and therefore were healthier, and could work more hours, and harder during those hours, for the same pay.
Moral: Don’t suck blood; Rockefeller hates competition.
Comment: In historical fact, Rockefeller did go after the hookworms, and for the reason stated; he didn’t want to share. He didn’t target vampires... but he would have.