OT: PowerPoint

Is there anyway to protect a Power Point presentation like you do an
Excel spreadsheet or Word document? I have been looking and I don't see
that you can do it. You could right click on the file and make it read
only or set the permissions to the file on the server. I would like
something that the users can do themselves that can't be easily undone.

I will keep looking and post if I find anything. Any help would be