checklist for secure pdf ebooks

Does anyone have a good checklist for making secure ebooks that can't be easily
copied or transmitted over file sharing networks? I think I have most of it
figured out but before I offer my book to the internet gods I just want to make
sure I did not miss anything.

Thanks to anyone with helpful info!

You cannot prevent files from being copied, you cannot even make it
difficult. A file is a file, and anyone can freely copy, share, email
it etc.

PDF ebook security is not based on stopping copying, but on DRM
(Digital Rights Management) which limits who, or what computer, can
open the file.

>Aandi to your response "freely" this is in conflict with those of
us who are trying sell our ebooks.

Of course it's in conflict with what you want. but you can't change
reality. This is not a question of preference, or design, but how the
web works. And why DRM is used.