(a)   No person, being engaged in picketing any place of employment, or being one of an assemblage gathered for the purpose of preventing or hindering the operation of that place, shall have in his possession any firearm, dirk, blackjack, billy, club or other weapon, or attempt to prevent any employee of the place, or any other person, from entering or leaving the same, by force or violence or by means of menacing threats, or by the use of threatening or abusive language.
   (b)   Whoever violates this section is guilty of a misdemeanor of the fourth degree.
(1979 Code 132.13)