Not Anvil staff, but…
There are various techniques using CSS or Javascript to disable text selection, disable the right-click menu, unbind or catch the keyboard text selection, but these are just deterrents to casual users and can be bypassed. There are also obfuscation techniques to make it harder for people looking at your page source. But short of using DRM, public key encryption, etc. I’m not aware of any absolute way to prevent plain text from being copied from a web resource.
Ken