Political Signs on Courthouse, Other County or City Property

It is illegal to post political signs on public property.

"21-2-3.(a) It shall be unlawful for any person to place campaign posters, signs, and advertisements:(1) Within the right of way of any public streets, roads, or highways;(2)  On any public property or building;(3) On any private property unless the owner thereof has given permission to place such campaign posters, signs, and advertisements on such property; or(4) Reserved;(5) On any property zoned for commercial or industrial uses if the placement of such campaign posters, signs, and advertisements conflicts with any zoning laws or ordinances.(b) Any person who violates this Code section shall be guilty of a misdemeanor."

Any ideas why this is not being enforced?