I created a book for someone and sent a PDF of it. I secured it with a password so it can be printed but not edited or copy/paste compatible. When I open the PDF on Acrobat on my PC, its locks me out as it should. I sent to friend and of course its the same way on Acrobat on his Mac. But when he opened it in "Preview" on the Mac, it lets him copy paste. He said he is using OSX Lion 10.7.4.
Why is Mac's viewer bypassing the security and how can I keep it from doing this?
A PDF consumer (viewer) is expected to honor any standard security restrictions that are in place, but there is no way to ensure that every one will. A different method that provides a strong form of security could be used, such as Certificate security or LiveCycle Rights Management (a type of DRM), but then non-Adobe viewers such as Preview wouldn't be able to open the document at all.
You can avoid the copy on Mac Preview by unchecking the option "Enable text access for screen reader devices for the visually impaired". That is all!