I use a credit union, and I have been the victim of a similar problem as the author, and the credit union folded in exactly the same way. Notably, the credit union is local to a state different from the one that tried to shake me down. I don't especially blame the credit union, though: they were upfront and communicative with me, and told me that their hands were tied.
The advice I was given (not by the CU): either withdraw all my money from the account and put it in a safe deposit box, or wire it to a (very) close relative ASAP -- before the lien is officially issued.