> This is a bit naive isn't it? Imagine contacting FINCEN, or whatever other appropriate regulatory agencies at the time of MtGox's founding when Bitcoin was a novelty and worth practically nothing. Imagine trying to explain to them what a "Bitcoin" is.

Much of the financial regulation that exists that would apply to MtGox has nothing to do with Bitcoin per se, it has to do with keeping customer accounts denominated in fiat currency and disbursing funds at customer direction from those accounts to accounts of other customers.