It is unlawful for any person to willfully or maliciously remove, destroy, alter or mutilate the number of any bicycle frame licensed pursuant to this chapter. It shall also be unlawful for any person to remove, destroy, alter or mutilate any license plate, seal or registration pursuant to this chapter; provided, however, that nothing in this chapter shall prohibit the Police Department from stamping numbers on the frames of bicycles on which no serial number can be found or on which said number may be illegible or insufficient for identification purposes. (Ord. 3451 § 1; Ord. 2670 § 1, 1996; Ord. 1641 § 1, 1975).