The New York Times
“In the commercial world, it is ubiquitous when credit is offered,” said Chris Jay Hoofnagle, a privacy advocate and senior fellow of the Berkeley Center for Law and Technology at the University of California, Berkeley. “It all flows from the credit system and it flows very far.”
The nine-digit string took on a third role — as a password that was supposed to protect all that private information from snoops and criminals. But its ubiquity defeats that purpose, Mr. Hoofnagle said. “It will pass when the business community no longer needs a Social Security number,” he said.