It is unlawful to hinder, annoy or molest persons passing along any street, sidewalk, crosswalk or other public way, or to lie, sit or stand around the entrance of any church, theater, public building or other place of public assemblage in any manner so as to unreasonably obstruct such entrance, or to place or erect upon any public way an obstruction of any type except temporary barriers or warning signs placed for the purpose of safeguarding the public against any hazard. (1996 Code § 9.08.100)