He has bankruptcy protection. He has no legal obligation to say anything right now.
I'm sorry to say this, but in reality he has no protection at all. Legal protection is a joke. If someone with the right connections or enough power wants to get to him, be it a government organization or a criminal organization they will. No protection on earth can protect him, and he should be very very afraid. But I don't think he's much afraid, as he seems completely disconnected from everything, he just does not function like a normal individual.
I don't have information one way or another that pertains to Mark, but you don't need to do much googling before you find countless cases about people getting into 'accidents' whose crime is to go against the wrong people or sticking their nose into something they didn't want to stick it into.
So any legal protection only goes as far as its respected by people overall. Legality is set aside every day. Mark not speaking about the situation only makes everything worse from the standpoint of the community.
I think most people put far too much trust into 'lawyers', 'police', 'judges' and the 'legal system'. These people are corrupted and compromized every day of the week around the globe, and if you can pay enough - you will have the best lawyers.
If Mark wanted to, he could sit down with someone independent, and everything could be mapped together, and presented to the community. But he never will - there's no interest in him for cleaning up his act, because he's a selfish bastard that do not care two cents about anyone else.
You can bet your life on the fact that he's stashed away enough btc for a lifetime to come though. Some people say that he can't run. He could if he wanted to. Some people point to the fact that he has a wife and a daughter. They don't realize that some men would drop their family in a heartbeat if that meant they could not have 500 million dollars in hand.