Sending currency to non-existant addresses is how people encode arbitary data on the bitcoin blockchain, so definitely possible. Giving a person control over t

Sending currency to non-existant addresses is how people encode arbitary data on the bitcoin blockchain, so definitely possible. Giving a person control over the funds allocated to their smart contract probably opens holes where they can steal the smart contract's money, though obviously creating software that handles money and can't be updated is its own kettle of fish.