If you're a terror suspect, you'd better have paid your taxes. The Social Security Administration and the IRS released private information–ranging from SSNs to occupations–on an ad hoc basis to the FBI for 9/11 investigations.
The Open Government Project at the Electronic Privacy Information Center obtained internal memorandums and records from the agencies through a Freedom of Information Act request. The SSA and IRS insist that there were no abuses of information.
Writing about "Real I.D." in January, Brian Doherty wore shades and a scarf to cover his bruises and lamented, "how little our 'partners' in D.C.–supposedly our agents, in fact, representing our own interests and using only powers we've ceded them–really respect us." Just imagine what the FBI would do with national ID cards, on an ad hoc basis only, of course.