Claude watermark bypassed within hours of rollout

The rapid emergence of watermark-removal tools exposes a fundamental tension in the EU's AI Act enforcement: the requirement to label synthetic content is technically sound in principle, but the invisible watermarking method Anthropic chose—SynthID, developed by Google and deployed since 2023—can be circumvented by straightforward text-manipulation techniques. Meyer and others argue the issue is not whether watermarking should exist, but whether invisible watermarks are the right mechanism. Because Anthropic's watermark works by influencing word choice in ways imperceptible to humans, any tool that rewrites or translates the text can potentially remove it. The regulatory deadline creates urgency: 190 organizations have signed the EU's transparency code, meaning multiple major providers will soon deploy similar systems. However, the fact that Meyer's removal method relies on unwatermarked large language models suggests the circumvention may have an expiration date—once most major models watermark their output, finding a non-watermarked alternative to do the rewriting will become harder. Anthropic's planned detection API is meant to verify the integrity of its own watermarking system, but as Wayne Pan notes, "I don't think you can ever have a watermark that will withstand everything," suggesting this may become an ongoing arms race between regulators and developers.