There's no reason you cannot construct a token that can be frozen and reversed - USDT (other issues as side) being an example.
Accounts as we know them don't have to be at the level of public address-private key but rather a smart contract as seen by Loopring.
The difference is what was centralised is now decentralised, what was implicit and required trust is now explicit and requires formal verification.
The difference is what was centralised is now decentralised, what was implicit and required trust is now explicit and requires formal verification.