User hostile UI in the name of security is particularly bad: we are supposed to type unique and complicated passwords in text fields without being able to see what we type, and if we get it wrong, we are put in timeout for two seconds. Citrix Netscaler nowadays apparently wants to be extra secure and shows you the most generic error message if you have a typo in either your password or user name and just tells you to "try again later", so you do until you lock yourself out. It's madness.
The Penny supermarkt app on android disables both screenshots and text selection with the error that it is disabled by admin.
These seems a bit like a scam. Why can't they ask the recevier?
It is fine for historical documents, but doing today means you really want to piss people off. And by the way, PDF files support signatures, both handwritten and digital. There are ways other than printing a 100+ page document and scanning it just so that your signature shows up on a single one of these pages.