I am not sure if you are aware but your PDF files can be edited if not password protected. I did not know this until I started working with PDF files on a more regular basis. Unsecure PDF files can be edited by anyone who has the Pro version of Adobe.
If not password protected your PDF file can be edited, copied or content such as clip art, can be stolen with a click of the mouse.
If you create anything that is going to be put out the general public, I strongly encourage you to protect your work by adding security to your document. Here is a brief tutorial that will show you how to secure your files and protect your hard work and intellectual property.
I love to help others grow and learn. If you have an idea for a tutorial be sure to post it in the comments.