Haha why is there "fiduciary" duty when Coinbase is not a bank, not a security agency, and not any type of share that people bought into (ie customers are not shareholder). Coinbase can do anything they want! Also, I suggest it's people's own fault for storing their bitcoins at a place that does not give access to their own private keys. This fork has been a long time coming. Everyone and their mother was warned to k…
That's no how laws work. Not even remotely. Thankfully.
Consider you order somebody (X) to transport your pregnant cow. At the destination the cow arrives. It's not pregnant anymore and X refuses to give you the calf because... well, because he can do anything he wants.
That's theft.