One of the arguments made against the way that Google does its ad services is through a process they call “Smart Bidding”.
The concern with this system I’ve heard is that even though Google doesn’t directly sell your information to advertisers, they show sensitive data like a user ID and device ID to advertisers along with your ad profile when this “Smart Bidding” takes place.
Do we have a source on whether this is actually true or not though? I’ve not seen any direct evidence that the particularly sensitive data like user ID or device ID are actually shown to advertisers.
When you enable smart bidding, Google uses additional sensitive data like user/device IDs to optimize your ads/bids on their end. They aren’t leaking that information to advertisers directly, and I can’t find anyone claiming that’s the case.
You’d have to provide a link to such a claim if you want us to evaluate a specific claim, otherwise I don’t know what they’d be referring to.