Would a gag order hide the warrant? This could explain why no one is suing the FBI.
http://en.wikipedia.org/wiki/Sovereign_immunity
You can't generally sue them unless they physically maim or kill you. Government privilege.
For instance, I doubt the constitution provides for this immunity.
I think that this immunity is not legal.
But maybe I missed some text in the constitution that grants it.
About as close to the Star Chamber as exists in the US judicial system. Basically the rules of FISA warrant include "you cannot talk about FISA warrant."
If a FISA warrant were served, it would kind of excuse DigitalOne's behavior in the whole thing to some extent.