A lot of people didn’t care to disable “Sent from my iPhone”. Many kept it as a sign of fashion. Some android users faked it even.
If this becomes a thing, then low end models may mimic the watermark of high end models. And maybe longer texts will counter it with cryptographically signed watermarks.
Anthropic says new Claude models will embed invisible watermarks in all generated text, everywhere Claude is offered.
The watermark is part of the text, it isn't metadata: "it will travel with the text when it's copied and pasted elsewhere, and may persist through some editing."
This starts with models launched on or after August 2, 2026, under an EU AI Act code Anthropic signed. Anthropic is still working on adding it to current models. The rollout is worldwide.