Log-in details from 1.6 million accounts have been posted on the web by hacktivist group Ghost Shell.
The group gathered the data during a series of attacks on Nasa, the FBI, the European Space Agency and many other government agencies and contractors.
Included in the dump were log-in names, passwords, email addresses and CVs, plus the contents of online databases.
The group said it had sent messages to security bosses about 150 insecure servers it had targeted in the attacks.
In a statement posted to the Pastebin website, Ghost Shell said the attacks were part of its #ProjectWhiteFox campaign to promote freedom of information online.
Source: BBC News