How do you know data is copied to their servers?

> If you serve as a mere conduit for automatic transmission of user communications, there are no other qualifications or obligations you need to meet. If you serve a caching function, in addition to the two requirements above, you must maintain comply with the notice-and-takedown process.

https://www.copyright.gov/512/

https://internetcases.com/2024/02/12/dmca-subpoena-to-mere-c...