If you go to this URL on JMP Public, you will be asked to sign in, and you won't be able to see this post because it is private.
https://public.jmp.com/packages/Distributions-with-URL/js-p/5bbe32de76c3ca068862419b
However, i can embed this private content in an iFrame. This seems like a hole. This is on public.jmp.com