2.0 Immutable Balances
Steem has a firm commitment to property rights, no hard forking change that reduces a user’s existing account balance of Steem, Steem Dollars, or Steem Power will be allowed. These balances may only be changed as the result of an operation signed by the account holder(s). These balances also include any funds held as open orders on the internal market.
What about in the case of a stolen account? The owner should be explicitly defined if we're bringing up property and the rights surrounding it. Is it the entity holding the key? Is it the person who it was stolen from?
Steem is built to incentivize long-term holding, but how does that affect what a thief would do with an account, especially if it's a valuable one? It could be disruptive. What if the account name is used as an identity widely? Would impersonation of this person be tolerated? Hypotheticals like this mean ownership needs to be defined.
Same situation: how to prove one is the owner of a coin on the ground?
Well that's not a good comparison, a coin on the ground doesn't have a name engraved in it, nor does it have a history of its changes in a blockchain.