Have Someone By The Short Hairs Meaning

(idiomatic) To have someone in a difficult situation in which he or she is without alternatives and can be controlled.

Example: 1960, P. G. Wodehouse, Jeeves in the Offing, chapter XIX:
  Beginning with a curt “Listen, Buster,” she proceeded to sketch out with admirable clearness the salient points in the situation as she envisaged it, and judging from the loud buzzing noises that came over the wire, clearly audible to me though now standing in the background, it was evident that the nub was not escaping him. They were the buzzing noises of a man slowly coming to the realization that a woman's hand had got him by the short hairs.
2002 June 7, Martin Peretz, "Power Trip," The New Republic (retrieved 16 Oct. 2007):
  The Saudis know that as long as we consume 7 billion barrels per year (4 billion of them imported from abroad), they have us by the short hairs.