Discussion at home: If I wanted to, say, sell a book via my own website, is there a way to make it so that only the person who bought it can read the file? I’d like them to be able to open it as many times as they want, but they don’t get to just click “Copy” and send it to a friend. Not asking for specific instructions, just wondering if this is easily doable.
I assume that if they have the ability to print it, then b it could be exported into a “clean” pdf, which could be shared.
No, that’s not easily doable. It’s not something you could do with standard PDF at all. There are document DRM solutions that can do something like this but they require special viewer applications and typically also a server infrastructure to enforce their restrictions.
I’m mean if it’s on a screen, you can always just take a picture of it with your phone. There is no 100% fool proof way of doing it.