Episode 3 ripped off the Masters Of Horror episode "Cigarette Burns"
Thats pretty much what it did, Cigarettes Burns which was an episode in the horror anthology show Masters Of Horror, heres the plot
"a movie theatre owner is hired to search for the only existing print of a film so notorious that its single screening caused the viewers to become homicidally insane."
Its not beat for beat what they did in the American Horror Stories episode but they took the basic idea of it which was about a film that was made a long time ago that caused people to go homicidally insane when watching it.
I did like the twist at the end with the guy selling it to netflix and the entire world would be able to watch it, that was pretty clever.