Comment by VincePlatt

So.. yeah, the bottom line here is that the font has to render from something.

In this case, it's rendering from a hidden input element:

<input id="ghost-font-message" class="GhostFontLanding_messageInput__La9Ij" type="text" maxlength="36" placeholder="SECRET MESSAGE" autocomplete="off" spellcheck="false" value="HELLO HUMAN">

Gee.. yeah, that's entirely indecipherable.

If you want to erect security between AI and content, then ...

yeah, just don't bother. It's not even worth the trouble and it's quite likely impossible at scale anyway.