U.S.: More than 21 million Social Security numbers stolen

Hackers stole Social Security numbers from more than 21 million people and snatched other sensitive information in a recent breach of U.S. government computer systems, the Obama administration said Thursday.

The U.S. Office of Personnel Management said Thursday that more than 19 million who applied for background investigations had their information compromised, as well as nearly 2 million of their family members -- like spouses or cohabitants -- who never applied for a background check.

OPM Director Katherine Archuleta said that, in addition to Social Security numbers, hackers took information about people's criminal, financial, health, employment and residency histories, as well as information about their families and acquaintances. She said hackers got hold of the user names and passwords that prospective employees used to fill out their background investigation forms, as well as the contents of interviews conducted as part of those investigations.

Archuleta said there was no evidence that payroll records were stolen. The administration also said there were no indications that the hackers have used the data they stole.

House Oversight and Government Reform Committee Chairman Jason Chaffetz, a Utah Republican, repeated his call Thursday for Archuleta and her chief information officer to resign immediately.

"Their negligence has now put the personal and sensitive information of 21.5 million Americans into the hands of our adversaries," Chaffetz said in a statement. "Such incompetence is inexcusable."

Archuleta said she would not be resigning in the wake of the breaches. "I am committed to the work that I am doing," she said in a conference call with reporters Thursday.

Investigators previously told The Associated Press that the U.S. government was increasingly confident that China's government, and not criminal hackers, was responsible for the extraordinary theft of personal information. China has publicly denied involvement in the break-in.

The administration acknowledged earlier this month that hackers stole the personnel files and background investigations of current and former civilian, intelligence and military employees, contractors and even job applicants. Initially, the U.S. said the stolen data included Social Security numbers, birth dates, job actions and other private information for 4.2 million workers.