[mothered]

I've always figured those private sites have a form of immunity to takedowns, no?

A takedown Is a takedown- It makes no difference whether It's private or how well protected they "seem" to be.

Copyright Infringement Is taken very seriously, and those who think they can escape even with the best legal representation, are kidding themselves. They may stall the process via appeals and some loophole, but eventually they'll get done.