The stolen hard drives however, did not contain Facebook users' data.
According to a CNBC report on Friday, Facebook said the hard drives contained unencrypted personal data of current and former employees and alerted those employees to the theft "out of an abundance of caution".
The hard drives contained information on thousands of US workers who were employed by Facebook in 2018.
"The company also failed to notify employees until almost a full month after the break-in occurred on November 17," The Verge said in a report.
An internal email revealed Facebook only realized the hard drives were missing on November 20, and confirmed that the drives contained employee information on November 29.
The social networking platform is now offering its employees two-year subscriptions to an identity theft protection service.
It is surprising that hard disks containing financial data was unencrypted.