The same way cash in your bank fit disappear even though you no authorize am? Banks sef fit close down without paying customers their balance. At least with Bitcoin, everything is fully transparent.
I usually think that if Bank closed down all the money people has putting there will be gone but from some persons is refunded that if anything happen to the bank they would look for a way to settle everybody, and I believe that is true because if is not and people learnt that banks are not entitled for repayments they would have withdrawn there money to some other things because banks may decide to come up anything anytime in terms of theft, though I'm not comparing it with the transparency of Bitcoin but I'm clearing the fact that Banks may not disappear with anybody's money like that.