I wonder if this is for use in future legal battles over ownership/creation/invention of new software and/or concepts.

For example, someone inventing a new technology might use AI to assist with code prototypes/doc prep etc. Where would that leave the rights of the owner/creator/inventor. These text watermarks provide fuel for legal battles.

Am I wrong?

I think the goal is not to validate if you used Claude, the goal is to insert enough information in your code to identify who you are over at Anthropic, like a covert unique hash to identify you, hidden in plain sight, but that's my own speculation and not based on anything.

I'm having a hard time thinking of any other use case... What other reason is there to fingerprint your code?

I assume if they arrest you for vibe coding something that violated computing laws (hacking) they can then scan your code, send it to anthropic, anthropic confirms that Claude was used on your account, on x device to build malware.

Remember they busted a hacker because of his Windows unique install ID.

My guess would be to detect if their models are being distilled by other models.