70 ILCS 3110/20
Any holder of bonds or of any of the coupons thereto appertaining and the trustee, except to the extent the rights herein given may be restricted by any resolution authorizing the issuance of, or by any trust agreement securing, such bonds, may, either at law or in equity, by suit, action mandamus, or other proceedings, protect and enforce any and all rights under the laws of this State or granted hereunder or under such resolution or trust agreement, and may enforce and compel the performance of all duties required by this Act or by such resolution or trust agreement to be performed by the Service or by any officer, employee, or agent thereof, including the fixing, charging, and collecting of rates, rentals, fees, and charges herein authorized and required by the provisions of such resolution or trust agreement to be fixed, charged, and collected.
70 ILCS 3110/20