-they will just go silent and everything is lost
I believe that this is the most likely one as it costs zero effort, and they end up with millions in tainted coin funds as bonus. It doesn't matter what they do at this point, they are already being painted off as criminals, so what exactly will change for them in that regard? Nothing.
But well, you understand that we are over this stage already? They did not go silent, you noticed that, right? So, the idea of "btce is stealing the same way like the FBI, then go silent and hide" can be dismissed already.