You can do a little research on ways to make it more difficult to copy content from a web page, the plugin doesn’t have this built into it. Implementing this will likely require you create a custom template to add the needed code.
I’m not familiar with the best ways to do this currently, but my understanding is you can make it more difficult, but you can’t prevent it because of how the web works: if something is displayed, the content is already on the user’s computer, loaded by the browser.
Streamed assets like audio and video are a bit different, you can often disable downloading in the player. This isn’t done in the Participants Database plugin, but in how you have the streamed content configured.
