Since you've mentioned about darknet and FBI, makes me wonder in which country was Chip Mixer established?
ChipMixer is not established in any country. As btce arrest show - if US wants to close you down they dont care where you are or what law protection you have.
Let's be real, the only reason Vinnick was pursued by the US is because he's Russian and accused to be a cyber criminal (not really bullshit on the accusation, but I believe in innocence until proven guilty).
That said, the US has brought down DPR and Burt W. and both have had questionable charges placed against them.
What do you do? You reside off shore, you keep your connection to your customers at a strictly business level, and you protect yourself from any entity that would have the power to force you out if they see you as a threat.
In as much as everyone wants to believe that Bitmixer closed down because of government pressure, but he has even come out to say the reason he is closing down which is due to morality from what I could pick from his statement and I personally feel the market is so large enough that when one close down, another is coming up again. In the case of Chipmixer, since this is now seen as the next alternative, I say brace for impact because winter is coming...