Sorry, there is always a 3rd party involved in a library. The librarians are the ones that select which books to have on handle for consumption, same with a book store, or any source provider of books.

A person going to a library and consuming with out a check-out record, one must assume any book was consumed with in the collection. Only a solid record of a book be checked out creates a defined moment that is still anchored in confidentiality between the parties.

Unless that microwave sensor requires an external communication it is a closed system which does not communicate any information about what item was heated. The 3rd party would be the company the meal was purchased from.

A well designed _smart microwave_ would perform batch process updating and pull in a collection of information to create the automated means to operate. Never know when there could be an Internet outage or the tool might be placed were external communication is not a possible option.

A poorly designed system would require a back and forth communication. Yet it would be no different than a chief knowing what you order with limited information about you. Those systems have an inherent anonymity.

It is the processing record that can be exploited and a good organization would require a warrant or purge the information when it is no longer needed. Cash payment also improves the anonymity in that style of system preventing leaking personal information to anyone.

Why should a static book system like a library not be applied to any ML model since they are performing the same task and providing access to information in a collection? The system is poorly designed if confidently is not adhered by all parties.

Sounds like ML corporations want to make you the product instead of being used as a product. This is why I only respect open design models, from bottom up, that are run locally.