The Massive OPM Hack Actually Hit 21 Million People
Found on Wired on Friday, 10 July 2015
“The team has now concluded with high confidence that sensitive information, including the Social Security Numbers (SSNs) of 21.5 million individuals, was stolen from the background investigation databases,” OPM wrote in the statement.
In June, after the hack was first publicly acknowledged, the government said the breach exposed the personal information of approximately four million people—and the information stolen only included data such as Social Security numbers, birth dates and addresses of current and former federal workers.
By now it should be pretty obvious that any sensitive data never should be on an Internet-facing system. If it needs to be stored electronically, use at least air-gapped systems.