I think MtGox agreed to US jurisdiction, thus it may allow a very quick injunction to freeze all Gox assets that a Japanese court would probably just assent to due to the agreement of jurisdiction. I would keep all funds out of Gox until you can see this taking years or not.
The contract is governed by laws of Canada, USA and Japan, if any of the these countries' law or regulation weren't complied with - the contract is void (it is actually is in the contract).
Data privacy laws, were they followed in all three countries?
Financial regulations of selling private accounts?
Ok there is the classic battle of the forms as to which jurisdiction apply
but in the case where both parties agree to a jurisdiction, then the matter is 99% of the time heard there, and most other countries court will accept this in a civil case.
You don't have to sell anything or reveal any private data. You just in-junct Mt. Gox from removing funds---however usual precedent is an injunction will not sound against normal trade, as if the suit fails, it will have done un reparable damage, and normal trade is just that, not money hiding/siphon off. Further Mt Gox could argue that its is in CL interests to do normal trade as this give more possible money to pay out.