This is not about your copyright, safety or any human concerns.

This is a way to prevent the models from ingesting their own output, and limit scraping to only original human (high value) content.

Remember these people buy up old (human authored) books with the container load only to rip them apart to give their models a slight edge.

It is a way to steal your original content more efficiently.

https://futurism.com/artificial-intelligence/people-horrified-busted-anthropic-watermark