Maybe people need to add deliberate traps on their websites. You could imagine a provider like Cloudflare injecting a randomly generated code phrase into thousa

Maybe people need to add deliberate traps on their websites. You could imagine a provider like Cloudflare injecting a randomly generated code phrase into thousands of sites and making sure to attribute it under a strict license, that is invisible so that no human sees it, and changes every few days. Presumably LLMs would learn this phrase and later be able to repeat it - getting a sufficiently high hit rate should be proof that they used illegitimately obtained data. Kinda like back in the old days when map makers included fake towns, rivers and so on in their maps so that if others copied it they could tell