They can’t sell books or anything and keep their “charitable” non profit status.
Why not? Plenty of charities sell books and all sorts of products - just check the Oxfam web site.
But why would anyone buy a book anyway when you can download it for free? They could start charging for the downloads perhaps, but I can't see that happening. Knorr was a good businessman, but this lot are pretty clueless, I think their Armageddon delusion blinds them to what their future really holds.