It was odd that they came back telling him used books sales was crowdfunding. They seemed to get that wrong. After that it was a bunch of useless corporate spam emails of the like you get from an App Store review or similar.
It also looks like the site changed from the initial email to later emails but the author is confused as to why stripe is confused.
http://www.beitesheldonate.org/ was maybe first website? Then a books website?
What can happen is they look into things more closely and see they are doing donations perhaps without a clear exempt entity (ie, not setup as a charity) or any number of things.
Anyways, to say that stripe should be shut down and is the "Gestapo" seems a bit misplaced. The crimes and methods of the Gestapo were truly horrific if you pay attention to WWII history - I'm still having trouble connecting stripe's behavior to the Gestapo.
I am quite cognizant of what the Gestapo did. They discriminated slowly but surely on the basis of the religious identify of people who were Jewish. Our church was Messianic Jewish as was indicated on the site. Some of our members had, in fact, relatives in the Holocaust.
His description seems very clearly a bookstore. He even names a book.
The rejection is very vague. Maybe he got more detail later. It would be helpful if for example it’s a non exempt entity, they specifically told him that so he could decide to remedy or appeal if they were incorrect.