Is it the fence or the guns on each side of the fence. My brothers high school girl friends family went under the Berlin wall. Her mom was pregnant with her at the time.
I had to research it several years ago after seeing references to it on The Peoples Cube. Good fodder for a satirical website considering our current commander in chief.
To top all of that was internet combined with limited education and religious belief, mix well, then add some Jim Jones idiot and kaboom.
As long as we allow religious belief to have any respect over reason, then we'll have idiots that want non-believers punished.