You know how Google Translate works? Same material in different languages to build a giant Rosetta stone. The "pirated" is in inverted commas. They are the biggest legal "pirates" of books on the planet and won a court case on scanning copyright works without licence by a technicality.
https://en.wikipedia.org/wiki/Google_Books
This is kind and doesn't mention the other ways that Google gets texts.
Google is the worst choice for that plugin. I'm happy to use online free for a phrase or two, but I'd prefer to pay a human for a translation. So while The Golem is free in German, I bought a decent English translation.
I don't go for conspiracy theories, but there is a reason why Google tools are "free".
This is offered free to websites and it's abusive and privacy busting. It's a valuable resource for Google.
https://en.wikipedia.org/wiki/ReCAPTCHA
AI is ultimately a lie. It's databases scraped from human content for free.
Edit: Update 2023-09-01
https://www.theguardian.com/technolo...ng-its-content
https://www.theguardian.com/technolo...-written-by-ai