It depends. If you can see the content of someone else's cBook, that means that, the original author has decided to share the content with a group of others including you.  The author may have set the cBook permissions so that you may be restricted to reading the content or he may have enabled you to copy and reuse content as you wish.  When content is copied within Cellucidate, the details of the activity are tracked, so that attribution to originating authors can be appropriately maintained.