In the long human effort to distinguish the made from the found, the authored from the generated, Anthropic has introduced an invisible signature into the text produced by its Claude AI — a statistical fingerprint woven into inconsequential word choices, designed to satisfy the European Union's AI Act without disturbing the surface of the prose. The watermark does not shout; it whispers, detectable only by those who hold the key. It is a compliance measure dressed as a technical achievement, and its quiet arrival suggests that the industry has chosen legibility to regulators over resistance to