Hackers affiliated with the online activist group Anonymous claim to have stolen tens of thousands of encrypted military passwords from U.S. contractor Booz Allen Hamilton and posted them to the Web.
The group boasted of stealing passwords linked to some 90,000 military users, although The Associated Press counted only about 67,000 unique email addresses, of which about 53,000 carried ".mil" domains.
The Pentagon said it was aware of the incident and coordinating with other federal partners on the matter.
Booz Allen released a statement Monday saying that its security policy meant it didn't usually comment on threats or attacks against its systems.
A spokesman for the Booz Allen Hamilton Holding Corp. declined any further comment.