There is no contract with the person found to be using it - the terms and conditions are irrelevant.
If they had taken it (for a valid reason) from the *rightful holder* with whom they have a contract then those things apply e.g. receipt, withdrawal. Just be grateful they didn't handle it with gloves and put it into a sealed evidence bag!
If they had taken it (for a valid reason) from the *rightful holder* with whom they have a contract then those things apply e.g. receipt, withdrawal. Just be grateful they didn't handle it with gloves and put it into a sealed evidence bag!