OIG Response:

  We acknowledge that almost none of the numberholders discussed in the 
  report currently receive SSA payments. However, SSA issued each of these 
  individuals a valid SSN and these SSNs could allow for a wide range of 
  potential abuse. 

  [...]

  We also note we initiated our 2015 review upon the receipt of information 
  that a man opened several bank accounts using SSNs belonging to 
  numberholders born in the 1800s who had no death information on the 
  Numident. In addition to being used to obtain employment or open bank 
  accounts, identity thieves can potentially use these SSNs to create 
  synthetic identifies, obtain credit, government benefits, or private 
  insurance.