HA!
The graffiti freaks will be feverishly spray-painting clothes on them.
Wall is only good if Manned by Troops. Idea: Form a new Branch of the Military—The Border Guard—Like the Coast Guard on Land. Put forts on Border, give em armored cars and propeller driven planes—P-51s maybe to strafe illegal “spies” in the five mile kill zone. Maybe some Robots as well—armored and armed with chain guns. Make the wall air tight! Only guarded gates provide access.