It's not Netfix, and it's not a series, but I have been binge watching 20/20 on Hulu and I watched an episode last week that literally blew my mind.
It's Season 44, Episode 7 "Escape From a House of Horror"
Most of 20/20 shows are about murder and wrongful conviction (which happens all too frequently) but, without spoiling too much, this was about a family of two parents and 13 children. The children were not allowed out of the house and were subjected to crazy cruelties. What blew my mind was the two girls who were interviewed were 27 and 33 years old and still spoke like excited little children. When they were rescued, they didn't know many common words and were wide-eyed, frightened, youngsters.
They lived in a neighborhood of cluster homes and it just blew me away that it could happen!