(1) It is unlawful for a mutual association to pledge, mortgage, or hypothecate to a depositor any of its real or personal property as security for a deposit, and any pledge, mortgage, or hypothecation made in violation of this section is unenforceable.
(2) This section does not apply to deposits of the money of the United States, public funds deposited in accordance with the provision of a depository act of this state or the United States, or bankruptcy estate funds or deposits, including deposits of receivers or trustees in bankruptcy, deposited under the discretion and supervision of a court of record of Montana or of the United States.