A hacker on Monday published information that exposes the names, titles, phone numbers, and e-mail addresses for thousands of FBI employees, after leaking similar data about 9,000 Department of Homeland Security employees Sunday, reports U.S. News and World Report.

A Twitter account used by the hacker linked to the DHS and FBI personnel data along with messages suggesting support for a free Palestine and promising to leak data about thousands more workers unless the U.S. ends diplomatic relations with Israel.

The hacker or hackers gained access to the federal staff data through the e-mail account of a Justice Department worker, which was also used to contact tech blog Motherboard to explain the hack. Motherboard reports it confirmed the leak was genuine by calling some of the phone numbers posted online. The Twitter account @DotGovs also posted a screenshot of the Justice Department website said to have provided the federal staff database.

In addition to the information from some 20,000 FBI employees, the hacker also told the tech blog that they have downloaded 200GB of data, including credit card numbers and military e-mails from the database, but they claimed the compromised e-mail gave them access to 1TB of information. ​​Motherboard said it was not able to verify that claim.