January 32: how to know if an AI trained on your content, and prove it

I had a hunch, and it turned out to be published. The idea was simple: if I mark my content before publishing it, and an AI model trains on it, that model should carry the mark inside. And if someone takes that model to train another one, a Chinese one for example, the new one carries it too. A trail that spreads down the chain of models like radioactive ink. The second part of the hunch was the carrier. The most stubborn way to plant that trail is not cryptography or metadata. It's an…