I'm not a fan of this question, or any question where all the answers are going to consist of "My predictions are", "I think", and "It seems". But others don't appear to feel the same way. What is the enduring value to the internet of this question? And who exactly are the experts we believe are on the site now, ready to answer a question like this authoritatively?
The question could easily be saved by changing it very slightly. I agree that as asked it just invites speculation more about what the US would be willing to do than about what systemic weaknesses crypto-currencies have against well-funded or well-connected adversaries.
One important thing for a Q&A site is to avoid baseless discussion since it chases away serious expert contributors. Questions that encourage uninformed speculation can either be closed, or can be edited so they have factual answers.
On StackExchange sites it is generally best to first ask the poster to rephrase the question. But if it remains off-track, remember that all content is licensed Creative Commons Share and Share alike, and the consensus of participants and moderators on what best serves the site should be followed. So submit edits, or flag posts.
In this case rephrasing it to discuss technical and legal attacks by well funded governments would make it more factual and less speculative.
I am having problems asking holistic questions. The holistic question I attempted to ask was: "What are the systemic weaknesses of crypto-currencies?" (thanks to the other answerer here). However, asking the question like this will often attract closing votes, therefore I often attempted to make the question more specific by adding things like the "US government". If you believe that the question would be better if changed to the other question, then I would be happy to edit it.
Specifying that I am only interested in technical or legal risks, will severely reduce the value of the answers, as the question might be focusing on risks that are neglectable, while ignoring bigger risks.
As for whether there are anyone on the site who are experts on answering the question, does not matter, as long as the question is relevant. Not asking questions that one guesses are too difficult for the experts on the site is a bad solution.