Saw the 20/20 episode - Seems fake

Because it was fake. If you do some research, you'll find that neither them, their mother, or the filmmaker can keep their stories straight.

I too couldn't figure out how the boy with the Michael Meyer's mask got out that front door if the father always locked them in and took the only key when he left. They never once explained that in any interview or tv show. They just said "I knew he would be gone for three hours and so I left and kept walking" then when they said he walked into a bank with it on, and when he spoke he was so articulate, it just didn't gel.

By the way, the filmmaker's story about how she met them, also changes. She also stated that the father welcomed her with "open arms" when she first was invited over for dinner. Doesn't sound like some mean animalistic man who locked his family away from society to me.

Then of course you have the whole no arrests for locking your family in an apartment for 20 years thing combined with where the hell did the mom give birth and the whole social worker follow ups for welfare which they were receiving.

Nothing makes sense which is why a lot of journalists did some digging and just wrote this off as gorilla advertisement before Sundance. They never talk about being locked away in the film, it's just implied.

Joon: "you're out of your tree" Sam: "it's not my tree" 

I especially love the part when one of the brothers is showing off their "collection" of movies that consisted of like, 10 DVD's.

Also can't believe the fact that he even owns a PA system ($1500+) and professional video equipment while being "locked up" in a housing project without even a grade school education and zero computer skills (how did they learn to use everything??).