I don't know if the OP of this reddit thread is correct, but he says there are rules preventing Bitfinex withdrawing coins from BitGo wallets belonging to its customers until an arbitrator decides what to do.
Bitfinex emptied all BitGo wallets anyway, but whether that was legal is an interesting question.
looks like just about anyone can empty bitgo wallets. what a top line service it is. I reckon the next week or two is the vital time. we'll see whether bfx is solvent, how this shitcoin's supposed to work and whether there's gonna be any legal action. I can't imagine there won't be.