Personally identifiable information belonging to thousands of U.S. Department of Homeland Security employees has been published online after a hacker stole reams of data in a previously undisclosed breach at the government department earlier this year.

The breach includes names, job titles, and work contact information, such as email addresses, cell phone numbers, and office locations, of more than 40,000 people who work for the federal department, including border and immigration agents, cybersecurity staffers, and senior department officials.