I tend to agree. They could start with a reply that they have ceased and desisted from all money transfer businesses. (Maybe they were planning some in the future?)
That would put the ball in the other side of the court, and at least let the State define what they are concerned about.
That's completely stupid - Why would you say you've stopped doing something you were never doing in the first place?? Are you on crack, NewLiberty? The burden of proof is on the state, dum-dum. What you're suggesting would actually cause them more trouble.
I've gotten threatening letters from the government that didn't pertain to me in the past. I just filed them away and ignored them.
I've been working on the assumption that the Foundation is going to respond. That is more or less the Foundation's reason for being. So although ignoring it would also be a sort of message, it doesn't take a foundation to do that. You and me can do that on our own as you wisely observed.
Its something you learn in law school in America, how to be stupid in very specific ways.
If one doesn't choose to rely on the pervasive government ennui or patriotism and are going to respond, the easiest disinfectant is bright light. Show them what you do and what you don't do. The Sacramentoans don't know the answer either, so if you don't want better funded competition to spend their effort on motivating the regulators to find something wrong, you can show the regulators something right.
Invite audits, make them experts on Bitcoin, and teach them how it is good for people like them and us.
But just a little knowledge can be a dangerous thing. Even that has risks.