[vkou]

Fly-by-night ad networks might engage in this. Ad networks that are in the sights of regulators, and can be slapped with $X billion fines, that may well exceed the marginal revenue produced by improved tracking[1] are going to be a bit antsier around doing that sort of thing.

[1] How much more money will a $100B ad business make if they improved tracking accuracy by %1? It's some positive number, but significantly less than $1B.

[consumer451]

Would a top tier ad network be exposed to any liability if the fly-by-night did the sketchy work, then the top tier bought that “anonymized” data?

[vkou]

Probably not direct legal risk[1] if they weren't the ones collecting the data, but integrating with all that shit has the incredible risk that your counterparty might just go up in smoke next week, while leaving you with a busted product, and all the reputational damage fallout.

It's picking up pennies in front of a steamroller. You'd have to be a truly desperate PM to consider it.

[1] Still all the legal risks of holding that data, but they are easier to mitigate.

[luma]

So instead they buy that data from the fly-by-night operators and carry on as usual. That's the key problem here, this data only needs to be collected by one shady operator, "the market" will handle the rest.