This actually is a reply to a closed post on suing the FBI for defamation: http://www.expertlaw.com/forums/showthread.php?t=83775

The expert responded that one cannot sue the FBI for defamation due to "sovereign immunity". That's false.

I am not a U.S. lawyer. But the lawyer who answered this wasn't correct in his response.

First of all, anyone can launch a lawsuit. The issue is admissibility (first) then "being heard", by a judge, finally the objective is to "win". It's possible to launch a lawsuit that's automatically dismissed.

It's also possible to sue U.S. government employees under the Federal Tort Claims Act ("FTCA"), which allows certain kinds of lawsuits against federal employees who are acting within the scope of their employment.

The proper tort to use would be a "Bivens" complaint.

Where a U.S. citizen has a problem winning is in U.S. administration actions in national security cases and foreign affairs.

In that case, as Justice Emmett Sullivan noted (in 'Meshal v. Higgenbotham'), in 2014. Mr. Meshal was a U.S. citizen who had a shocking experience of being rendered to two different countries, by foreign govenrments, in a situation where FBI officials were complicit, and involved in his incarceration (during which time he was tortured). Mr. Meshal sued the FBI for torture, and the judge, however appalled he was by the FBI's behavior, was unable to do anything but dismiss the case, as he was "constrained by prior rulings". Justice Sullivan indicated that the place of recourse was/is the legislature (Congress).

Presumptively, if a person can't sue the FBI for torture (in national security cases) they can't sue for defamation.

So it's possible to sue the FBI.

You'd just best do it with a good lawyer, and evidence.

The FBI has been sued quite a bit, so yes, you can sue them.

Whether or not your case is dismissed, or if you win, is another matter.

If you want to read about Meshal v. Higgenbotham, go to the ACLU website. https://www.aclu.org/cases/meshal-v-higgenbotham