Even a whiff of that nonsense would crash the equity markets here and likely all over the world given the funds that invest in US companies. There would be nothing of any value for them to seize.
“I shut off inputs to my 401k months ago to prevent further loss, and I’m expecting to lose the entire balance, which I’m unable to yank so long as I’m still employed. “
I am in the same boat and did the same thing as you in Spring of 08 and even put it all in a money market position, so no stocks or mutual funds for my 401k right now. I still put in a very small amount monthly into my IRA, but the real retirement asset I have is my 401k. I hate letting it sit idle but given the economy the way it is....