It shall be unlawful for any person to wilfully or maliciously remove, destroy, mutilate or alter the number on any bicycle frame licensed pursuant to this chapter. It shall also be unlawful for any person to remove, destroy, mutilate or alter any license plate or registration card during the time in which such license plate or registration card is operative. 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 numbers are illegible or insufficient for identification purposes. (1960 Code, Sec. 7-1111; amd. Ord. 08-503, 6-3-2008)