Where an AI Watermark Can Hide in Plain Text

On August 11, 2026, Anthropic said it would start marking everything Claude writes. Two parts. Files like PNGs and SVGs get signed provenance metadata under the C2PA standard. Plain text gets what they call "an imperceptible watermark woven directly into the text itself," one that survives copy and paste.Bundling...Here's the catch: they didn't say how. No algorithm, no detector, no list of what the mark actually controls. So this isn't a teardown. It's a read on what they said, what it could be, and how people will get around it.The file half is simple and easy to beat. It's a signature on a container, so a screenshot or a format conversion drops it. The text half is the interesting one, and it's where Daniel pushed back.the part that shouldn't be possible His objection: Text is text, so when you copy text, what are the possible avenues for having watermarks? If you use basic ASCII in its most primitive form with uniform spacing, which is industry standard, there is literally no…