Such as the cryptsy theft? Would there be a way to roll back the block chain to undo the theft?
cryptsy "dun goxed" and blamed hackers from 18 months ago.. (we know vern ran with the money, hense why he closed the office to not be traced or slapped with a wet fish)
and strangely is now running a new exchange in china.
but lets play along with verns excuse of hacking
the only way to prevent hacking is not to have wallets on the same IP/server as the front-end (website).
this can be done so easily using databases to store requests and a separate server/system reads those requests and processes them OFFSITE.
that way the main server does not reveal the location of the offsite system because its not pushing data out. its just storing data locally and the offsite system looks in..
there should be no reason ever to have hotwallets on the server that the website front end is also on