Anything you put out there in the Internet (public pages) is available for anyone else to copy and save/re-use. So if you really want your content to be safe and protected - do not put it online.
But if you want you can try to protect your content/images and prevent/disable at least the most simple ways to copy it. In fact, anyone can "view source", check the browser cache for images, use "Print Screen" or "site copy" software, etc. - these things can't be disabled, but they require additional knowledge and skills than just selecting the content and copying it or dragging an image from browser window to the desktop.
This module includes several different technical ways/methods to make copying/stealing information/images from your site harder than it usually is:

Disable text selection
Disable copy to clipboard
Disable right-click context menu on all site content
Disable right-click context menu only on images (<img> tag)
Place transparent image above all your images - this will protect your real images from being saved using context menu or drag-and-drop to desktop
Protect/hide your images from search engine indexes so that your images don't show up in image searches - add "noimageindex" robots tag and disallow image files indexing in robots.txt

Some of these methods might make your site harder to use for less-advanced users and you should carefully consider all the implications of using these techniques. Drupal community is even considering adding dependency on Bad Judgement module - see this issue #1966018: Add bad judgement as a dependency.

Installation

Just download and install as any other Drupal module. Then configure the options at "admin/config/user-interface/copyprevention" - all the methods are disabled by default.
The user permission (admin/people/permissions) "Bypass Copy prevention" allows to not apply these module methods to trusted user roles.

RTBC issues for Copy Prevention

Filters