How can I protect from copy/paste or duplication?

Hello,

We have a few online eLearning courses that we would like to convert to a PDF.  This is a popular request from our students.

One of the reasons we have not done this is that we don't want to  compromise our copyright by having a competitor copy our hard work.

Is there a way to protect a PDF document from being copied?  I know that  if there is a will, there is a way and that we won't stop somebody who  is hell bent on copying it.

We do have Adobe Acrobat Pro 9 if that helps.  Any ideas on what we could do and how to best protect the document?

Thanks!

-Dave