I'm going by this document from the Irish Council for Civil Liberties and a lawsuit brought against Google, signed by member of Congress, that alleged data brokers are "siphoning" off bid-stream data and reselling it . It makes the claim that U.S Dept of Homeland Security uses real-time bidding data for warrant-less phone tracking.

https://www.iccl.ie/wp-content/uploads/2022/05/Mass-data-bre...

https://www.tampabay.com/news/2021/05/07/google-selling-user...

I get the desire for a smoking gun. Maybe one exists and someone else interested in the subject could share it. But at some point, people make judgement calls based off of the information made public. I would bet my original assertion is true, and that Google data is somehow being sold to the federal government, to build dossiers on it's citizens. Same with E.U. citizens.