Once they have the data, they can do whatever they want with it. They can run it through closed-source ML, they can sell it to other companies. I suppose people would know if they meddled with the news feed order, but that's about it.
Thats rather cynical... Sure!! The team of privacy and security activists backed by internet hall of fame member Phil Zimmerman who created PGP and fought the US govt are all actually closeted evil capitalists just out to get everyones data..
