The course materials are among the most frequently hacked and on stolen content. The best thing you can do is to implement as many safeguard options as possible.
Allow your users to add their own copyright policy. This would be especially useful for the companies that sell online courses or educational books.
Block the Copy functionality for your content.
Add watermarks with the name of your website or author of the course.
Timestamp the content of your users. It will be useful if the material will appear on another resource and this will help you prove that the content belongs to your website.
Make sure that there’s non paid access to the content. Instead of providing the trials before users actually subscribe to a course expose only several paragraphs of your content or first minutes of the videos.