An anonymous hacker on Monday made good on his threat to post the details of 20,000 FBI employees online, less than 24 hours after he dumped the data for 10,000 Department of Homeland Security (DHS) personnel.

The hacker, who claims to have obtained the information by hacking the Department of Justice, shared both datasets with Motherboard in advance of the hack. The publication performed a spot check and found that most of the names, email addresses and job descriptions — including around 1,000 intelligence analysts — appear to be legitimate.

Officials have downplayed the alleged breach.

A DHS spokesperson said this morning that the agency is looking into the purported disclosure but that “there is no indication at this time that there is any breach of sensitive or personally identifiable information.”