We'd see them spend it and ask what they've spent it on.

I'd expect the CIA to know how to launder money competently. It seems like a ridiculously obvious thing for them to learn how to do.

Given bitcoin's current quasi-legal status, I don't think they'd be under any obligation to answer that question until the coins become legal tender

And they would say "none of your business."

Do you think that possibility translates into enthusiasm in the Senate?