Claude's invisible watermarks cracked within hours; override code gets 20k bookmarks

deliprao · x · 2026-08-24

Anthropic announced last week that Claude would globally embed invisible, machine-readable watermarks in AI-generated text to comply with the EU AI Act. Within four hours, developer Guillaume Meyer published his override. The watermark-removal code went viral on GitHub, drew over 20,000 bookmarks on X and 100+ contributors, with many folding the technique into their own projects.

The new rules require providers like Anthropic and OpenAI to label synthetic audio, image, video, or text so machines can detect it as AI-generated, on pain of fines up to 3% of annual turnover. Meyer says some evade the watermark on principle — opposing mandatory labeling of all AI content — while others, himself included, relish the technical challenge; freelance writers and social creators have asked him for help using the code.

Researcher Delip Rao quoted the story to argue the literature covered this long ago, and that WIRED should have written about how out-of-touch EU AI regulators are — with Anthropic researchers knowing this "safety" feature was dead on arrival and shipping it purely as bureaucratic compliance.

Related event: Claude's Invisible Watermark Cracked Within Hours, Sparking Debate on AI Watering Regulation(2 posts)→

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