The Internal Revenue Service is reporting a potential security breach involving personal information about 20,000 IRS workers, former workers and contractors.
IRS Commissioner John Koskinen said Tuesday an employee took home a computer thumb drive containing names, Social Security numbers and addresses of the workers.
Koskinen says the drive was plugged into the employee's unsecure home network, putting it at risk for public release. However, he says there has been no evidence the information has been used inappropriately.
Almost all the employees worked at IRS offices in Pennsylvania, New Jersey and Delaware. The information dates back to at least 2007.
Koskinen says the agency's inspector general is investigating the potential breach. An IRS spokeswoman has declined to comment on the status of the employee who took home the data.
Explore further: Official-looking e-mails claiming to be from IRS are fraudulent